diff --git a/README.md b/README.md
index 5a7e7ed..3d62592 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,8 @@
 # Codex Document Format
 
+[![Validate Schemas](https://github.com/gvonness-apolitical/codex-file-format-spec/actions/workflows/validate-schemas.yml/badge.svg)](https://github.com/gvonness-apolitical/codex-file-format-spec/actions/workflows/validate-schemas.yml)
+[![License](https://img.shields.io/badge/License-Apache_2.0-blue.svg)](LICENSE)
+
 **An open specification for documents that unify viewing and editing, with modern security and machine readability.**
 
 > Status: Draft Specification (v0.1)
diff --git a/examples/academic-document/academic/numbering.json b/examples/academic-document/academic/numbering.json
new file mode 100644
index 0000000..3b4bfc6
--- /dev/null
+++ b/examples/academic-document/academic/numbering.json
@@ -0,0 +1,22 @@
+{
+  "version": "0.1",
+  "equations": {
+    "style": "number",
+    "resetOn": "chapter"
+  },
+  "theorems": {
+    "style": "chapter.number",
+    "counters": {
+      "theorem": { "share": ["lemma", "proposition", "corollary"] },
+      "definition": { "share": [] }
+    }
+  },
+  "algorithms": {
+    "style": "number",
+    "resetOn": "none"
+  },
+  "exercises": {
+    "style": "chapter.number",
+    "resetOn": "chapter"
+  }
+}
diff --git a/examples/academic-document/content/document.json b/examples/academic-document/content/document.json
new file mode 100644
index 0000000..acf4924
--- /dev/null
+++ b/examples/academic-document/content/document.json
@@ -0,0 +1,392 @@
+{
+  "version": "0.1",
+  "blocks": [
+    {
+      "type": "heading",
+      "id": "title",
+      "level": 1,
+      "children": [
+        { "type": "text", "value": "Introduction to Analysis" }
+      ]
+    },
+    {
+      "type": "paragraph",
+      "id": "intro",
+      "children": [
+        { "type": "text", "value": "This document demonstrates the academic extension with theorems, proofs, exercises, equations, and algorithms." }
+      ]
+    },
+    {
+      "type": "heading",
+      "id": "ch1",
+      "level": 2,
+      "children": [
+        { "type": "text", "value": "Chapter 1: Foundations" }
+      ]
+    },
+    {
+      "type": "academic:theorem",
+      "variant": "definition",
+      "id": "def-continuous",
+      "number": "1.1",
+      "children": [
+        {
+          "type": "paragraph",
+          "children": [
+            { "type": "text", "value": "A function " },
+            { "type": "text", "value": "f: X -> Y", "marks": [{ "type": "math", "format": "latex", "source": "f: X \\to Y" }] },
+            { "type": "text", "value": " is " },
+            { "type": "text", "value": "continuous", "marks": ["bold"] },
+            { "type": "text", "value": " at a point " },
+            { "type": "text", "value": "x_0", "marks": [{ "type": "math", "format": "latex", "source": "x_0" }] },
+            { "type": "text", "value": " if for every " },
+            { "type": "text", "value": "epsilon > 0", "marks": [{ "type": "math", "format": "latex", "source": "\\epsilon > 0" }] },
+            { "type": "text", "value": " there exists " },
+            { "type": "text", "value": "delta > 0", "marks": [{ "type": "math", "format": "latex", "source": "\\delta > 0" }] },
+            { "type": "text", "value": " such that " },
+            { "type": "text", "value": "|x - x_0| < delta implies |f(x) - f(x_0)| < epsilon", "marks": [{ "type": "math", "format": "latex", "source": "|x - x_0| < \\delta \\implies |f(x) - f(x_0)| < \\epsilon" }] },
+            { "type": "text", "value": "." }
+          ]
+        }
+      ]
+    },
+    {
+      "type": "academic:theorem",
+      "variant": "theorem",
+      "id": "thm-ivt",
+      "number": "1.2",
+      "title": "Intermediate Value Theorem",
+      "uses": ["#def-continuous"],
+      "children": [
+        {
+          "type": "paragraph",
+          "children": [
+            { "type": "text", "value": "Let " },
+            { "type": "text", "value": "f: [a,b] -> R", "marks": [{ "type": "math", "format": "latex", "source": "f: [a,b] \\to \\mathbb{R}" }] },
+            { "type": "text", "value": " be continuous. If " },
+            { "type": "text", "value": "y", "marks": [{ "type": "math", "format": "latex", "source": "y" }] },
+            { "type": "text", "value": " is between " },
+            { "type": "text", "value": "f(a)", "marks": [{ "type": "math", "format": "latex", "source": "f(a)" }] },
+            { "type": "text", "value": " and " },
+            { "type": "text", "value": "f(b)", "marks": [{ "type": "math", "format": "latex", "source": "f(b)" }] },
+            { "type": "text", "value": ", then there exists " },
+            { "type": "text", "value": "c in (a,b)", "marks": [{ "type": "math", "format": "latex", "source": "c \\in (a,b)" }] },
+            { "type": "text", "value": " such that " },
+            { "type": "text", "value": "f(c) = y", "marks": [{ "type": "math", "format": "latex", "source": "f(c) = y" }] },
+            { "type": "text", "value": "." }
+          ]
+        }
+      ]
+    },
+    {
+      "type": "academic:proof",
+      "of": "#thm-ivt",
+      "method": "construction",
+      "qed": "symbol",
+      "children": [
+        {
+          "type": "paragraph",
+          "children": [
+            { "type": "text", "value": "Without loss of generality, assume " },
+            { "type": "text", "value": "f(a) < y < f(b)", "marks": [{ "type": "math", "format": "latex", "source": "f(a) < y < f(b)" }] },
+            { "type": "text", "value": ". Define " },
+            { "type": "text", "value": "S = {x in [a,b] : f(x) < y}", "marks": [{ "type": "math", "format": "latex", "source": "S = \\{x \\in [a,b] : f(x) < y\\}" }] },
+            { "type": "text", "value": ". The set " },
+            { "type": "text", "value": "S", "marks": [{ "type": "math", "format": "latex", "source": "S" }] },
+            { "type": "text", "value": " is non-empty (contains " },
+            { "type": "text", "value": "a", "marks": [{ "type": "math", "format": "latex", "source": "a" }] },
+            { "type": "text", "value": ") and bounded above by " },
+            { "type": "text", "value": "b", "marks": [{ "type": "math", "format": "latex", "source": "b" }] },
+            { "type": "text", "value": ". Let " },
+            { "type": "text", "value": "c = sup S", "marks": [{ "type": "math", "format": "latex", "source": "c = \\sup S" }] },
+            { "type": "text", "value": ". By continuity, " },
+            { "type": "text", "value": "f(c) = y", "marks": [{ "type": "math", "format": "latex", "source": "f(c) = y" }] },
+            { "type": "text", "value": "." }
+          ]
+        }
+      ]
+    },
+    {
+      "type": "paragraph",
+      "id": "thm-ref-example",
+      "children": [
+        { "type": "text", "value": "By " },
+        {
+          "type": "text",
+          "value": "Theorem 1.2",
+          "marks": [
+            {
+              "type": "theorem-ref",
+              "target": "#thm-ivt",
+              "format": "Theorem {number}"
+            }
+          ]
+        },
+        { "type": "text", "value": ", every polynomial of odd degree has a real root." }
+      ]
+    },
+    {
+      "type": "heading",
+      "id": "sec-equations",
+      "level": 2,
+      "children": [
+        { "type": "text", "value": "Multi-Line Equations" }
+      ]
+    },
+    {
+      "type": "academic:equation-group",
+      "environment": "align",
+      "id": "eq-taylor",
+      "lines": [
+        {
+          "value": "e^x &= \\sum_{n=0}^{\\infty} \\frac{x^n}{n!}",
+          "number": "1",
+          "id": "eq-exp"
+        },
+        {
+          "value": "&= 1 + x + \\frac{x^2}{2!} + \\frac{x^3}{3!} + \\cdots",
+          "number": null
+        },
+        {
+          "value": "\\sin x &= \\sum_{n=0}^{\\infty} \\frac{(-1)^n x^{2n+1}}{(2n+1)!}",
+          "number": "2",
+          "id": "eq-sin"
+        },
+        {
+          "value": "\\cos x &= \\sum_{n=0}^{\\infty} \\frac{(-1)^n x^{2n}}{(2n)!}",
+          "number": "3",
+          "id": "eq-cos"
+        }
+      ]
+    },
+    {
+      "type": "paragraph",
+      "id": "eq-ref-example",
+      "children": [
+        { "type": "text", "value": "From " },
+        {
+          "type": "text",
+          "value": "(1)",
+          "marks": [
+            {
+              "type": "equation-ref",
+              "target": "#eq-exp",
+              "format": "({number})"
+            }
+          ]
+        },
+        { "type": "text", "value": " and " },
+        {
+          "type": "text",
+          "value": "(2)",
+          "marks": [
+            {
+              "type": "equation-ref",
+              "target": "#eq-sin",
+              "format": "({number})"
+            }
+          ]
+        },
+        { "type": "text", "value": ", we can derive Euler's formula." }
+      ]
+    },
+    {
+      "type": "heading",
+      "id": "sec-algorithms",
+      "level": 2,
+      "children": [
+        { "type": "text", "value": "Algorithms" }
+      ]
+    },
+    {
+      "type": "academic:algorithm",
+      "id": "alg-bisection",
+      "number": "1",
+      "title": "Bisection",
+      "caption": "Root finding by bisection method",
+      "lineNumbering": true,
+      "inputs": [
+        { "name": "f", "description": "Continuous function" },
+        { "name": "a, b", "description": "Interval endpoints with f(a)f(b) < 0" },
+        { "name": "tol", "description": "Tolerance" }
+      ],
+      "outputs": [
+        { "name": "c", "description": "Approximate root" }
+      ],
+      "lines": [
+        { "content": "\\textbf{while} |b - a| > \\text{tol} \\textbf{do}", "label": "loop" },
+        { "content": "c \\gets (a + b) / 2", "indent": 1, "label": "midpoint" },
+        { "content": "\\textbf{if} f(c) = 0 \\textbf{then}", "indent": 1 },
+        { "content": "\\textbf{return} c", "indent": 2 },
+        { "content": "\\textbf{else if} f(a) \\cdot f(c) < 0 \\textbf{then}", "indent": 1 },
+        { "content": "b \\gets c", "indent": 2 },
+        { "content": "\\textbf{else}", "indent": 1 },
+        { "content": "a \\gets c", "indent": 2 },
+        { "content": "\\textbf{end if}", "indent": 1 },
+        { "content": "\\textbf{end while}", "label": "endloop" },
+        { "content": "\\textbf{return} (a + b) / 2", "comment": "approximate root" }
+      ]
+    },
+    {
+      "type": "paragraph",
+      "id": "alg-ref-example",
+      "children": [
+        { "type": "text", "value": "The loop at " },
+        {
+          "type": "text",
+          "value": "line 1",
+          "marks": [
+            {
+              "type": "algorithm-ref",
+              "target": "#alg-bisection",
+              "line": "loop",
+              "format": "line {line}"
+            }
+          ]
+        },
+        { "type": "text", "value": " of " },
+        {
+          "type": "text",
+          "value": "Algorithm 1",
+          "marks": [
+            {
+              "type": "algorithm-ref",
+              "target": "#alg-bisection",
+              "format": "Algorithm {number}"
+            }
+          ]
+        },
+        { "type": "text", "value": " converges linearly." }
+      ]
+    },
+    {
+      "type": "heading",
+      "id": "sec-exercises",
+      "level": 2,
+      "children": [
+        { "type": "text", "value": "Exercises" }
+      ]
+    },
+    {
+      "type": "academic:exercise",
+      "id": "ex-1",
+      "number": "1.1",
+      "difficulty": "easy",
+      "children": [
+        {
+          "type": "paragraph",
+          "children": [
+            { "type": "text", "value": "Prove that " },
+            { "type": "text", "value": "f(x) = x^2", "marks": [{ "type": "math", "format": "latex", "source": "f(x) = x^2" }] },
+            { "type": "text", "value": " is continuous at " },
+            { "type": "text", "value": "x = 0", "marks": [{ "type": "math", "format": "latex", "source": "x = 0" }] },
+            { "type": "text", "value": " using the epsilon-delta definition." }
+          ]
+        }
+      ],
+      "hints": [
+        {
+          "type": "paragraph",
+          "children": [
+            { "type": "text", "value": "Try " },
+            { "type": "text", "value": "delta = sqrt(epsilon)", "marks": [{ "type": "math", "format": "latex", "source": "\\delta = \\sqrt{\\epsilon}" }] },
+            { "type": "text", "value": "." }
+          ]
+        }
+      ],
+      "solution": {
+        "visibility": "spoiler",
+        "children": [
+          {
+            "type": "paragraph",
+            "children": [
+              { "type": "text", "value": "Given " },
+              { "type": "text", "value": "epsilon > 0", "marks": [{ "type": "math", "format": "latex", "source": "\\epsilon > 0" }] },
+              { "type": "text", "value": ", choose " },
+              { "type": "text", "value": "delta = sqrt(epsilon)", "marks": [{ "type": "math", "format": "latex", "source": "\\delta = \\sqrt{\\epsilon}" }] },
+              { "type": "text", "value": ". Then " },
+              { "type": "text", "value": "|x| < delta implies |x^2| < delta^2 = epsilon", "marks": [{ "type": "math", "format": "latex", "source": "|x| < \\delta \\implies |x^2| < \\delta^2 = \\epsilon" }] },
+              { "type": "text", "value": "." }
+            ]
+          }
+        ]
+      }
+    },
+    {
+      "type": "academic:exercise",
+      "id": "ex-2",
+      "number": "1.2",
+      "difficulty": "medium",
+      "children": [
+        {
+          "type": "paragraph",
+          "children": [
+            { "type": "text", "value": "Let " },
+            { "type": "text", "value": "f(x) = x^3 - x - 1", "marks": [{ "type": "math", "format": "latex", "source": "f(x) = x^3 - x - 1" }] },
+            { "type": "text", "value": "." }
+          ]
+        }
+      ],
+      "parts": [
+        {
+          "label": "a",
+          "children": [
+            {
+              "type": "paragraph",
+              "children": [
+                { "type": "text", "value": "Show that " },
+                { "type": "text", "value": "f", "marks": [{ "type": "math", "format": "latex", "source": "f" }] },
+                { "type": "text", "value": " has a root in " },
+                { "type": "text", "value": "(1, 2)", "marks": [{ "type": "math", "format": "latex", "source": "(1, 2)" }] },
+                { "type": "text", "value": "." }
+              ]
+            }
+          ],
+          "solution": {
+            "visibility": "hidden",
+            "children": [
+              {
+                "type": "paragraph",
+                "children": [
+                  { "type": "text", "value": "We have " },
+                  { "type": "text", "value": "f(1) = -1 < 0", "marks": [{ "type": "math", "format": "latex", "source": "f(1) = -1 < 0" }] },
+                  { "type": "text", "value": " and " },
+                  { "type": "text", "value": "f(2) = 5 > 0", "marks": [{ "type": "math", "format": "latex", "source": "f(2) = 5 > 0" }] },
+                  { "type": "text", "value": ". By the IVT, there exists a root in " },
+                  { "type": "text", "value": "(1, 2)", "marks": [{ "type": "math", "format": "latex", "source": "(1, 2)" }] },
+                  { "type": "text", "value": "." }
+                ]
+              }
+            ]
+          }
+        },
+        {
+          "label": "b",
+          "children": [
+            {
+              "type": "paragraph",
+              "children": [
+                { "type": "text", "value": "Apply three iterations of the bisection method." }
+              ]
+            }
+          ],
+          "solution": {
+            "visibility": "hidden",
+            "children": [
+              {
+                "type": "paragraph",
+                "children": [
+                  { "type": "text", "value": "Iteration 1: " },
+                  { "type": "text", "value": "c = 1.5, f(1.5) = 0.875 > 0", "marks": [{ "type": "math", "format": "latex", "source": "c = 1.5, f(1.5) = 0.875 > 0" }] },
+                  { "type": "text", "value": ", so root is in " },
+                  { "type": "text", "value": "(1, 1.5)", "marks": [{ "type": "math", "format": "latex", "source": "(1, 1.5)" }] },
+                  { "type": "text", "value": "." }
+                ]
+              }
+            ]
+          }
+        }
+      ]
+    }
+  ]
+}
diff --git a/examples/academic-document/manifest.json b/examples/academic-document/manifest.json
new file mode 100644
index 0000000..e83f999
--- /dev/null
+++ b/examples/academic-document/manifest.json
@@ -0,0 +1,24 @@
+{
+  "codex": "0.1",
+  "id": "pending",
+  "state": "draft",
+  "created": "2025-01-28T14:00:00Z",
+  "modified": "2025-01-28T14:00:00Z",
+  "extensions": [
+    {
+      "id": "codex.academic",
+      "version": "0.1",
+      "required": false
+    }
+  ],
+  "content": {
+    "path": "content/document.json",
+    "hash": "sha256:e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855"
+  },
+  "metadata": {
+    "dublinCore": "metadata/dublin-core.json"
+  },
+  "academic": {
+    "numbering": "academic/numbering.json"
+  }
+}
diff --git a/examples/academic-document/metadata/dublin-core.json b/examples/academic-document/metadata/dublin-core.json
new file mode 100644
index 0000000..124a6c7
--- /dev/null
+++ b/examples/academic-document/metadata/dublin-core.json
@@ -0,0 +1,14 @@
+{
+  "version": "1.1",
+  "terms": {
+    "title": "Introduction to Analysis",
+    "creator": ["Dr. Jane Smith"],
+    "subject": ["mathematics", "analysis", "calculus"],
+    "description": "A demonstration of academic extension features including theorems, proofs, exercises, and algorithms.",
+    "date": "2025-01-28",
+    "type": "Text",
+    "format": "application/vnd.codex+zip",
+    "language": "en",
+    "rights": "CC BY 4.0"
+  }
+}
diff --git a/examples/collaboration-document/collaboration/changes.json b/examples/collaboration-document/collaboration/changes.json
new file mode 100644
index 0000000..97c3376
--- /dev/null
+++ b/examples/collaboration-document/collaboration/changes.json
@@ -0,0 +1,80 @@
+{
+  "version": "0.2",
+  "baseVersion": "sha256:abc123def456789012345678901234567890123456789012345678901234",
+  "crdtFormat": "yjs",
+  "changes": [
+    {
+      "id": "change-1",
+      "type": "insert",
+      "anchor": { "blockId": "obj-4" },
+      "position": { "after": "obj-3" },
+      "author": {
+        "name": "Bob Martinez",
+        "email": "bob@example.com",
+        "userId": "user-002",
+        "color": "#4ecdc4"
+      },
+      "timestamp": "2025-01-28T09:00:00Z",
+      "status": "accepted"
+    },
+    {
+      "id": "change-2",
+      "type": "modify",
+      "anchor": { "blockId": "para-timeline" },
+      "before": {
+        "type": "paragraph",
+        "children": [
+          { "type": "text", "value": "The project is estimated to require 6 months for initial deployment, with an estimated budget of $100,000." }
+        ]
+      },
+      "after": {
+        "type": "paragraph",
+        "children": [
+          { "type": "text", "value": "The project is estimated to require 6 months for initial deployment, with an estimated budget of $150,000. Phase 1 will focus on core functionality, with subsequent phases adding advanced features." }
+        ]
+      },
+      "author": {
+        "name": "David Lee",
+        "email": "david@example.com",
+        "userId": "user-004",
+        "color": "#dda0dd"
+      },
+      "timestamp": "2025-01-28T11:00:00Z",
+      "status": "accepted"
+    },
+    {
+      "id": "change-3",
+      "type": "format",
+      "anchor": { "blockId": "title" },
+      "before": { "level": 2 },
+      "after": { "level": 1 },
+      "author": {
+        "name": "Alice Chen",
+        "email": "alice@example.com",
+        "userId": "user-001",
+        "color": "#ff6b6b"
+      },
+      "timestamp": "2025-01-28T09:30:00Z",
+      "status": "accepted"
+    },
+    {
+      "id": "change-4",
+      "type": "delete",
+      "anchor": { "blockId": "removed-section" },
+      "before": {
+        "type": "paragraph",
+        "children": [
+          { "type": "text", "value": "This section was removed during editing." }
+        ]
+      },
+      "author": {
+        "name": "Carol Davis",
+        "email": "carol@example.com",
+        "userId": "user-003",
+        "color": "#95e1d3"
+      },
+      "timestamp": "2025-01-28T10:00:00Z",
+      "status": "pending"
+    }
+  ]
+}
diff --git a/examples/collaboration-document/collaboration/comments.json b/examples/collaboration-document/collaboration/comments.json
new file mode 100644
index 0000000..2452f1e
--- /dev/null
+++ b/examples/collaboration-document/collaboration/comments.json
@@ -0,0 +1,114 @@
+{
+  "version": "0.2",
+  "crdtFormat": "yjs",
+  "comments": [
+    {
+      "id": "comment-1",
+      "type": "comment",
+      "anchor": { "blockId": "para-1", "start": 78, "end": 100 },
+      "author": {
+        "name": "Alice Chen",
+        "email": "alice@example.com",
+        "userId": "user-001",
+        "color": "#ff6b6b"
+      },
+      "created": "2025-01-28T10:15:00Z",
+      "content": "Can we be more specific about what 'organizational efficiency' means in this context?",
+      "resolved": false,
+      "replies": [
+        {
+          "id": "reply-1-1",
+          "author": {
+            "name": "Bob Martinez",
+            "email": "bob@example.com",
+            "userId": "user-002",
+            "color": "#4ecdc4"
+          },
+          "created": "2025-01-28T10:30:00Z",
+          "content": "Good point. I'll add some metrics in the next revision."
+        },
+        {
+          "id": "reply-1-2",
+          "author": {
+            "name": "Alice Chen",
+            "email": "alice@example.com",
+            "userId": "user-001",
+            "color": "#ff6b6b"
+          },
+          "created": "2025-01-28T10:45:00Z",
+          "content": "Thanks! Consider including time savings and error reduction rates."
+        }
+      ]
+    },
+    {
+      "id": "comment-2",
+      "type": "highlight",
+      "anchor": { "blockId": "obj-2" },
+      "author": {
+        "name": "Carol Davis",
+        "email": "carol@example.com",
+        "userId": "user-003",
+        "color": "#95e1d3"
+      },
+      "created": "2025-01-28T11:00:00Z",
+      "content": "This is a key differentiator from our current system.",
+      "resolved": false
+    },
+    {
+      "id": "suggestion-1",
+      "type": "suggestion",
+      "anchor": { "blockId": "para-timeline", "start": 47, "end": 56 },
+      "author": {
+        "name": "David Lee",
+        "email": "david@example.com",
+        "userId": "user-004",
+        "color": "#dda0dd"
+      },
+      "created": "2025-01-28T11:30:00Z",
+      "originalText": "6 months",
+      "suggestedText": "8 months",
+      "status": "pending"
+    },
+    {
+      "id": "suggestion-2",
+      "type": "suggestion",
+      "anchor": { "blockId": "para-timeline", "start": 106, "end": 114 },
+      "author": {
+        "name": "David Lee",
+        "email": "david@example.com",
+        "userId": "user-004",
+        "color": "#dda0dd"
+      },
+      "created": "2025-01-28T11:32:00Z",
+      "originalText": "$150,000",
+      "suggestedText": "$200,000",
+      "status": "accepted"
+    },
+    {
+      "id": "reaction-1",
+      "type": "reaction",
+      "anchor": { "blockId": "para-conclusion" },
+      "author": {
+        "name": "Eve Wilson",
+        "email": "eve@example.com",
+        "userId": "user-005",
+        "color": "#ffd93d"
+      },
+      "created": "2025-01-28T12:00:00Z",
+      "emoji": "thumbsup"
+    },
+    {
+      "id": "reaction-2",
+      "type": "reaction",
+      "anchor": { "blockId": "para-conclusion" },
+      "author": {
+        "name": "Frank Brown",
+        "email": "frank@example.com",
+        "userId": "user-006",
+        "color": "#6c5ce7"
+      },
+      "created": "2025-01-28T12:05:00Z",
+      "emoji": "rocket"
+    }
+  ]
+}
diff --git a/examples/collaboration-document/content/document.json b/examples/collaboration-document/content/document.json
new file mode 100644
index 0000000..0c439fd
--- /dev/null
+++ b/examples/collaboration-document/content/document.json
@@ -0,0 +1,121 @@
+{
+  "version": "0.1",
+  "blocks": [
+    {
+      "type": "heading",
+      "id": "title",
+      "level": 1,
+      "children": [
+        { "type": "text", "value": "Project Proposal: Document Management System" }
+      ]
+    },
+    {
+      "type": "heading",
+      "id": "exec-summary",
+      "level": 2,
+      "children": [
+        { "type": "text", "value": "Executive Summary" }
+      ]
+    },
+    {
+      "type": "paragraph",
+      "id": "para-1",
+      "children": [
+        { "type": "text", "value": "This proposal outlines a new document management system designed to improve organizational efficiency and collaboration. The system will provide version control, access management, and real-time collaboration features." }
+      ]
+    },
+    {
+      "type": "heading",
+      "id": "objectives",
+      "level": 2,
+      "children": [
+        { "type": "text", "value": "Project Objectives" }
+      ]
+    },
+    {
+      "type": "list",
+      "id": "obj-list",
+      "ordered": true,
+      "children": [
+        {
+          "type": "listItem",
+          "id": "obj-1",
+          "children": [
+            {
+              "type": "paragraph",
+              "children": [
+                { "type": "text", "value": "Implement secure document storage with encryption" }
+              ]
+            }
+          ]
+        },
+        {
+          "type": "listItem",
+          "id": "obj-2",
+          "children": [
+            {
+              "type": "paragraph",
+              "children": [
+                { "type": "text", "value": "Enable real-time collaborative editing" }
+              ]
+            }
+          ]
+        },
+        {
+          "type": "listItem",
+          "id": "obj-3",
+          "children": [
+            {
+              "type": "paragraph",
+              "children": [
+                { "type": "text", "value": "Provide comprehensive audit trails" }
+              ]
+            }
+          ]
+        },
+        {
+          "type": "listItem",
+          "id": "obj-4",
+          "children": [
+            {
+              "type": "paragraph",
+              "children": [
+                { "type": "text", "value": "Support integration with existing enterprise systems" }
+              ]
+            }
+          ]
+        }
+      ]
+    },
+    {
+      "type": "heading",
+      "id": "timeline",
+      "level": 2,
+      "children": [
+        { "type": "text", "value": "Timeline and Budget" }
+      ]
+    },
+    {
+      "type": "paragraph",
+      "id": "para-timeline",
+      "children": [
+        { "type": "text", "value": "The project is estimated to require 6 months for initial deployment, with an estimated budget of $150,000. Phase 1 will focus on core functionality, with subsequent phases adding advanced features." }
+      ]
+    },
+    {
+      "type": "heading",
+      "id": "conclusion",
+      "level": 2,
+      "children": [
+        { "type": "text", "value": "Conclusion" }
+      ]
+    },
+    {
+      "type": "paragraph",
+      "id": "para-conclusion",
+      "children": [
+        { "type": "text", "value": "We believe this system will significantly improve document workflow and reduce operational costs. We recommend proceeding with Phase 1 immediately." }
+      ]
+    }
+  ]
+}
diff --git a/examples/collaboration-document/manifest.json b/examples/collaboration-document/manifest.json
new file mode 100644
index 0000000..43f82f5
--- /dev/null
+++ b/examples/collaboration-document/manifest.json
@@ -0,0 +1,25 @@
+{
+  "codex": "0.1",
+  "id": "pending",
+  "state": "draft",
+  "created": "2025-01-28T14:00:00Z",
+  "modified": "2025-01-28T14:00:00Z",
+  "extensions": [
+    {
+      "id": "codex.collaboration",
+      "version": "0.2",
+      "required": false
+    }
+  ],
+  "content": {
+    "path": "content/document.json",
+    "hash": "sha256:e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855"
+  },
+  "metadata": {
+    "dublinCore": "metadata/dublin-core.json"
+  },
+  "collaboration": {
+    "comments": "collaboration/comments.json",
+    "changes": "collaboration/changes.json"
+  }
+}
diff --git a/examples/collaboration-document/metadata/dublin-core.json b/examples/collaboration-document/metadata/dublin-core.json
new file mode 100644
index 0000000..15fb143
--- /dev/null
+++ b/examples/collaboration-document/metadata/dublin-core.json
@@ -0,0 +1,14 @@
+{
+  "version": "1.1",
+  "terms": {
+    "title": "Project Proposal: Document Management System",
+    "creator": ["Bob Martinez", "Alice Chen", "Carol Davis", "David Lee"],
+    "subject": ["project proposal", "document management", "collaboration"],
+    "description": "A demonstration of collaboration extension features including comments, suggestions, reactions, and tracked changes with multiple authors.",
+    "date": "2025-01-28",
+    "type": "Text",
+    "format": "application/vnd.codex+zip",
+    "language": "en",
+    "rights": "Confidential"
+  }
+}
diff --git a/examples/forms-document/content/document.json b/examples/forms-document/content/document.json
new file mode 100644
index 0000000..200931b
--- /dev/null
+++ b/examples/forms-document/content/document.json
@@ -0,0 +1,251 @@
+{
+  "version": "0.1",
+  "blocks": [
+    {
+      "type": "heading",
+      "id": "title",
+      "level": 1,
+      "children": [
+        { "type": "text", "value": "Conference Registration Form" }
+      ]
+    },
+    {
+      "type": "paragraph",
+      "id": "intro",
+      "children": [
+        { "type": "text", "value": "Please complete the following form to register for the Annual Technology Conference 2025." }
+      ]
+    },
+    {
+      "type": "forms:form",
+      "id": "registration-form",
+      "children": [
+        {
+          "type": "heading",
+          "id": "personal-info",
+          "level": 2,
+          "children": [
+            { "type": "text", "value": "Personal Information" }
+          ]
+        },
+        {
+          "type": "forms:textInput",
+          "id": "field-name",
+          "name": "fullName",
+          "label": "Full Name",
+          "placeholder": "Enter your full name",
+          "required": true,
+          "validation": {
+            "minLength": 2,
+            "maxLength": 100,
+            "message": "Please enter your full name (2-100 characters)"
+          },
+          "fallback": {
+            "type": "paragraph",
+            "children": [
+              { "type": "text", "value": "Full Name: _________________________________" }
+            ]
+          }
+        },
+        {
+          "type": "forms:textInput",
+          "id": "field-email",
+          "name": "email",
+          "label": "Email Address",
+          "placeholder": "you@example.com",
+          "required": true,
+          "inputType": "email",
+          "validation": {
+            "email": true,
+            "message": "Please enter a valid email address"
+          }
+        },
+        {
+          "type": "forms:textInput",
+          "id": "field-phone",
+          "name": "phone",
+          "label": "Phone Number",
+          "placeholder": "+1 (555) 123-4567",
+          "inputType": "tel",
+          "validation": {
+            "pattern": "^\\+?[0-9\\s\\-\\(\\)]+$",
+            "message": "Please enter a valid phone number"
+          }
+        },
+        {
+          "type": "heading",
+          "id": "employment-section",
+          "level": 2,
+          "children": [
+            { "type": "text", "value": "Employment Information" }
+          ]
+        },
+        {
+          "type": "forms:dropdown",
+          "id": "field-employment",
+          "name": "employmentType",
+          "label": "Employment Status",
+          "required": true,
+          "options": [
+            { "value": "employed", "label": "Employed" },
+            { "value": "self-employed", "label": "Self-Employed" },
+            { "value": "student", "label": "Student" },
+            { "value": "retired", "label": "Retired" },
+            { "value": "other", "label": "Other" }
+          ]
+        },
+        {
+          "type": "forms:textInput",
+          "id": "field-company",
+          "name": "companyName",
+          "label": "Company/Organization Name",
+          "placeholder": "Enter company name",
+          "conditionalValidation": {
+            "when": { "field": "employmentType", "equals": "employed" },
+            "then": {
+              "required": true,
+              "minLength": 2,
+              "message": "Company name is required for employed attendees"
+            }
+          }
+        },
+        {
+          "type": "forms:textInput",
+          "id": "field-job-title",
+          "name": "jobTitle",
+          "label": "Job Title",
+          "placeholder": "e.g., Software Engineer"
+        },
+        {
+          "type": "heading",
+          "id": "registration-section",
+          "level": 2,
+          "children": [
+            { "type": "text", "value": "Registration Options" }
+          ]
+        },
+        {
+          "type": "forms:radioGroup",
+          "id": "field-ticket",
+          "name": "ticketType",
+          "label": "Ticket Type",
+          "required": true,
+          "options": [
+            { "value": "standard", "label": "Standard ($299)" },
+            { "value": "premium", "label": "Premium with Workshops ($499)" },
+            { "value": "student", "label": "Student ($99)" },
+            { "value": "virtual", "label": "Virtual Attendance ($49)" }
+          ]
+        },
+        {
+          "type": "forms:dropdown",
+          "id": "field-sessions",
+          "name": "sessions",
+          "label": "Preferred Sessions",
+          "multiple": true,
+          "searchable": true,
+          "options": [
+            { "value": "ai-ml", "label": "AI & Machine Learning" },
+            { "value": "web-dev", "label": "Web Development" },
+            { "value": "security", "label": "Cybersecurity" },
+            { "value": "cloud", "label": "Cloud Computing" },
+            { "value": "mobile", "label": "Mobile Development" },
+            { "value": "data", "label": "Data Science" }
+          ]
+        },
+        {
+          "type": "forms:checkbox",
+          "id": "field-lunch",
+          "name": "includeLunch",
+          "label": "Include lunch package (+$50)"
+        },
+        {
+          "type": "heading",
+          "id": "dietary-section",
+          "level": 2,
+          "children": [
+            { "type": "text", "value": "Dietary Requirements" }
+          ]
+        },
+        {
+          "type": "forms:dropdown",
+          "id": "field-dietary",
+          "name": "dietaryRequirements",
+          "label": "Dietary Restrictions",
+          "options": [
+            { "value": "none", "label": "No restrictions" },
+            { "value": "vegetarian", "label": "Vegetarian" },
+            { "value": "vegan", "label": "Vegan" },
+            { "value": "halal", "label": "Halal" },
+            { "value": "kosher", "label": "Kosher" },
+            { "value": "gluten-free", "label": "Gluten-free" },
+            { "value": "other", "label": "Other (please specify)" }
+          ]
+        },
+        {
+          "type": "forms:textArea",
+          "id": "field-dietary-notes",
+          "name": "dietaryNotes",
+          "label": "Additional Dietary Notes",
+          "placeholder": "Please describe any allergies or special requirements",
+          "rows": 3,
+          "conditionalValidation": {
+            "when": { "field": "dietaryRequirements", "equals": "other" },
+            "then": {
+              "required": true,
+              "message": "Please specify your dietary requirements"
+            }
+          }
+        },
+        {
+          "type": "heading",
+          "id": "terms-section",
+          "level": 2,
+          "children": [
+            { "type": "text", "value": "Terms and Conditions" }
+          ]
+        },
+        {
+          "type": "forms:checkbox",
+          "id": "field-terms",
+          "name": "agreeTerms",
+          "label": "I agree to the terms and conditions",
+          "required": true,
+          "validation": {
+            "required": true,
+            "message": "You must agree to the terms and conditions to register"
+          }
+        },
+        {
+          "type": "forms:checkbox",
+          "id": "field-newsletter",
+          "name": "subscribeNewsletter",
+          "label": "Subscribe to our newsletter for updates"
+        },
+        {
+          "type": "forms:signature",
+          "id": "field-signature",
+          "name": "signature",
+          "label": "Signature",
+          "required": true,
+          "width": 400,
+          "height": 150
+        },
+        {
+          "type": "forms:datePicker",
+          "id": "field-date",
+          "name": "signatureDate",
+          "label": "Date",
+          "format": "YYYY-MM-DD",
+          "maxDate": "today",
+          "required": true
+        },
+        {
+          "type": "forms:submit",
+          "id": "submit-btn",
+          "label": "Complete Registration"
+        }
+      ]
+    }
+  ]
+}
diff --git a/examples/forms-document/forms/data.json b/examples/forms-document/forms/data.json
new file mode 100644
index 0000000..82617ee
--- /dev/null
+++ b/examples/forms-document/forms/data.json
@@ -0,0 +1,22 @@
+{
+  "version": "0.1",
+  "values": {
+    "fullName": "Jane Doe",
+    "email": "jane.doe@example.com",
+    "phone": "+1 (555) 123-4567",
+    "employmentType": "employed",
+    "companyName": "Acme Corporation",
+    "jobTitle": "Senior Software Engineer",
+    "ticketType": "premium",
+    "sessions": ["ai-ml", "cloud", "security"],
+    "includeLunch": true,
+    "dietaryRequirements": "vegetarian",
+    "dietaryNotes": "",
+    "agreeTerms": true,
+    "subscribeNewsletter": true,
+    "signature": "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mNk+M9QDwADhgGAWjR9awAAAABJRU5ErkJggg==",
+    "signatureDate": "2025-01-28"
+  },
+  "submitted": false,
+  "lastModified": "2025-01-28T15:30:00Z"
+}
diff --git a/examples/forms-document/manifest.json b/examples/forms-document/manifest.json
new file mode 100644
index 0000000..fc8db7c
--- /dev/null
+++ b/examples/forms-document/manifest.json
@@ -0,0 +1,21 @@
+{
+  "codex": "0.1",
+  "id": "pending",
+  "state": "draft",
+  "created": "2025-01-28T14:00:00Z",
+  "modified": "2025-01-28T14:00:00Z",
+  "extensions": [
+    {
+      "id": "codex.forms",
+      "version": "0.1",
+      "required": false
+    }
+  ],
+  "content": {
+    "path": "content/document.json",
+    "hash": "sha256:e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855"
+  },
+  "metadata": {
+    "dublinCore": "metadata/dublin-core.json"
+  }
+}
diff --git a/examples/forms-document/metadata/dublin-core.json b/examples/forms-document/metadata/dublin-core.json
new file mode 100644
index 0000000..0f207fa
--- /dev/null
+++ b/examples/forms-document/metadata/dublin-core.json
@@ -0,0 +1,14 @@
+{
+  "version": "1.1",
+  "terms": {
+    "title": "Conference Registration Form",
+    "creator": "Conference Organizers",
+    "subject": ["registration", "forms", "conference"],
+    "description": "A demonstration of forms extension features including text inputs, dropdowns, checkboxes, validation, conditional validation, and signatures.",
+    "date": "2025-01-28",
+    "type": "InteractiveResource",
+    "format": "application/vnd.codex+zip",
+    "language": "en",
+    "rights": "All rights reserved"
+  }
+}
diff --git a/examples/phantoms-document/content/document.json b/examples/phantoms-document/content/document.json
new file mode 100644
index 0000000..ce7a10c
--- /dev/null
+++ b/examples/phantoms-document/content/document.json
@@ -0,0 +1,95 @@
+{
+  "version": "0.1",
+  "blocks": [
+    {
+      "type": "heading",
+      "id": "title",
+      "level": 1,
+      "children": [
+        { "type": "text", "value": "Software Architecture Overview" }
+      ]
+    },
+    {
+      "type": "paragraph",
+      "id": "intro",
+      "children": [
+        { "type": "text", "value": "This document provides an overview of the system architecture, including key components and their interactions." }
+      ]
+    },
+    {
+      "type": "heading",
+      "id": "components",
+      "level": 2,
+      "children": [
+        { "type": "text", "value": "System Components" }
+      ]
+    },
+    {
+      "type": "paragraph",
+      "id": "para-components",
+      "children": [
+        { "type": "text", "value": "The system consists of three main components: the API Gateway, the Application Server, and the Database Layer. Each component is designed for horizontal scalability." }
+      ]
+    },
+    {
+      "type": "heading",
+      "id": "api-section",
+      "level": 3,
+      "children": [
+        { "type": "text", "value": "API Gateway" }
+      ]
+    },
+    {
+      "type": "paragraph",
+      "id": "para-api",
+      "children": [
+        { "type": "text", "value": "The API Gateway handles all incoming requests, performs authentication, rate limiting, and routes requests to appropriate services." }
+      ]
+    },
+    {
+      "type": "heading",
+      "id": "app-section",
+      "level": 3,
+      "children": [
+        { "type": "text", "value": "Application Server" }
+      ]
+    },
+    {
+      "type": "paragraph",
+      "id": "para-app",
+      "children": [
+        { "type": "text", "value": "The Application Server contains the business logic and processes requests from the API Gateway. It communicates with the Database Layer for data persistence." }
+      ]
+    },
+    {
+      "type": "heading",
+      "id": "db-section",
+      "level": 3,
+      "children": [
+        { "type": "text", "value": "Database Layer" }
+      ]
+    },
+    {
+      "type": "paragraph",
+      "id": "para-db",
+      "children": [
+        { "type": "text", "value": "The Database Layer provides data storage using a combination of PostgreSQL for relational data and Redis for caching." }
+      ]
+    },
+    {
+      "type": "heading",
+      "id": "deployment",
+      "level": 2,
+      "children": [
+        { "type": "text", "value": "Deployment Architecture" }
+      ]
+    },
+    {
+      "type": "paragraph",
+      "id": "para-deployment",
+      "children": [
+        { "type": "text", "value": "The system is deployed on Kubernetes, with each component running in its own pod. Auto-scaling is configured based on CPU and memory utilization." }
+      ]
+    }
+  ]
+}
diff --git a/examples/phantoms-document/manifest.json b/examples/phantoms-document/manifest.json
new file mode 100644
index 0000000..1d6bf6f
--- /dev/null
+++ b/examples/phantoms-document/manifest.json
@@ -0,0 +1,24 @@
+{
+  "codex": "0.1",
+  "id": "pending",
+  "state": "draft",
+  "created": "2025-01-28T14:00:00Z",
+  "modified": "2025-01-28T14:00:00Z",
+  "extensions": [
+    {
+      "id": "codex.phantoms",
+      "version": "0.1",
+      "required": false
+    }
+  ],
+  "content": {
+    "path": "content/document.json",
+    "hash": "sha256:e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855"
+  },
+  "metadata": {
+    "dublinCore": "metadata/dublin-core.json"
+  },
+  "phantoms": {
+    "clusters": "phantoms/clusters.json"
+  }
+}
diff --git a/examples/phantoms-document/metadata/dublin-core.json b/examples/phantoms-document/metadata/dublin-core.json
new file mode 100644
index 0000000..22f8771
--- /dev/null
+++ b/examples/phantoms-document/metadata/dublin-core.json
@@ -0,0 +1,14 @@
+{
+  "version": "1.1",
+  "terms": {
+    "title": "Software Architecture Overview",
+    "creator": "Engineering Team",
+    "subject": ["software architecture", "system design", "documentation"],
+    "description": "A demonstration of phantoms extension features including annotation clusters with different scopes (shared, role-based, private), phantom connections, and nested content.",
+    "date": "2025-01-28",
+    "type": "Text",
+    "format": "application/vnd.codex+zip",
+    "language": "en",
+    "rights": "Internal Use Only"
+  }
+}
diff --git a/examples/phantoms-document/phantoms/clusters.json b/examples/phantoms-document/phantoms/clusters.json
new file mode 100644
index 0000000..62d9a45
--- /dev/null
+++ b/examples/phantoms-document/phantoms/clusters.json
@@ -0,0 +1,191 @@
+{
+  "version": "0.1",
+  "clusters": [
+    {
+      "id": "cluster-architecture-notes",
+      "anchor": { "blockId": "para-components" },
+      "label": "Architecture Notes",
+      "scope": "shared",
+      "author": {
+        "name": "Sarah Johnson",
+        "email": "sarah@example.com",
+        "identifier": "https://orcid.org/0000-0002-1234-5678"
+      },
+      "created": "2025-01-28T09:00:00Z",
+      "metadata": {
+        "color": "#4a90d9",
+        "collapsed": false
+      },
+      "phantoms": [
+        {
+          "id": "phantom-1",
+          "position": { "x": 0, "y": 0 },
+          "size": { "width": 200, "height": 100 },
+          "content": {
+            "blocks": [
+              {
+                "type": "paragraph",
+                "children": [
+                  { "type": "text", "value": "Consider adding a message queue between API Gateway and App Server for async processing." }
+                ]
+              }
+            ]
+          },
+          "created": "2025-01-28T09:15:00Z",
+          "author": {
+            "name": "Sarah Johnson",
+            "email": "sarah@example.com"
+          }
+        },
+        {
+          "id": "phantom-2",
+          "position": { "x": 250, "y": 0 },
+          "size": { "width": 180, "height": 80 },
+          "content": {
+            "blocks": [
+              {
+                "type": "paragraph",
+                "children": [
+                  { "type": "text", "value": "RabbitMQ or Kafka?" }
+                ]
+              }
+            ]
+          },
+          "connections": [
+            { "target": "phantom-1", "style": "arrow", "label": "relates to" }
+          ],
+          "created": "2025-01-28T09:20:00Z",
+          "author": {
+            "name": "Mike Chen",
+            "email": "mike@example.com"
+          }
+        },
+        {
+          "id": "phantom-3",
+          "position": { "x": 125, "y": 130 },
+          "size": { "width": 200, "height": 60 },
+          "content": {
+            "blocks": [
+              {
+                "type": "paragraph",
+                "children": [
+                  { "type": "text", "value": "Kafka for high throughput, RabbitMQ for simpler setup" }
+                ]
+              }
+            ]
+          },
+          "connections": [
+            { "target": "phantom-2", "style": "dashed" }
+          ],
+          "created": "2025-01-28T09:25:00Z",
+          "author": {
+            "name": "Sarah Johnson",
+            "email": "sarah@example.com"
+          }
+        }
+      ]
+    },
+    {
+      "id": "cluster-security-review",
+      "anchor": { "blockId": "para-api" },
+      "label": "Security Review",
+      "scope": "role:security-team",
+      "author": {
+        "name": "Alex Security",
+        "email": "alex.sec@example.com"
+      },
+      "created": "2025-01-28T10:00:00Z",
+      "metadata": {
+        "color": "#e74c3c",
+        "collapsed": true
+      },
+      "phantoms": [
+        {
+          "id": "phantom-sec-1",
+          "position": { "x": 0, "y": 0 },
+          "size": { "width": 250, "height": 120 },
+          "content": {
+            "blocks": [
+              {
+                "type": "heading",
+                "level": 3,
+                "children": [
+                  { "type": "text", "value": "Security Checklist" }
+                ]
+              },
+              {
+                "type": "list",
+                "ordered": false,
+                "children": [
+                  {
+                    "type": "listItem",
+                    "checked": true,
+                    "children": [
+                      { "type": "paragraph", "children": [{ "type": "text", "value": "OAuth 2.0 implementation" }] }
+                    ]
+                  },
+                  {
+                    "type": "listItem",
+                    "checked": true,
+                    "children": [
+                      { "type": "paragraph", "children": [{ "type": "text", "value": "Rate limiting configured" }] }
+                    ]
+                  },
+                  {
+                    "type": "listItem",
+                    "checked": false,
+                    "children": [
+                      { "type": "paragraph", "children": [{ "type": "text", "value": "WAF rules reviewed" }] }
+                    ]
+                  }
+                ]
+              }
+            ]
+          },
+          "created": "2025-01-28T10:05:00Z",
+          "author": {
+            "name": "Alex Security",
+            "email": "alex.sec@example.com"
+          }
+        }
+      ]
+    },
+    {
+      "id": "cluster-personal-notes",
+      "anchor": { "blockId": "para-db" },
+      "label": "My Notes",
+      "scope": "private",
+      "author": {
+        "name": "Developer",
+        "email": "dev@example.com"
+      },
+      "created": "2025-01-28T11:00:00Z",
+      "metadata": {
+        "color": "#9b59b6",
+        "collapsed": false
+      },
+      "phantoms": [
+        {
+          "id": "phantom-private-1",
+          "position": { "x": 0, "y": 0 },
+          "size": { "width": 180, "height": 80 },
+          "content": {
+            "blocks": [
+              {
+                "type": "paragraph",
+                "children": [
+                  { "type": "text", "value": "TODO: Research TimescaleDB for time-series data" }
+                ]
+              }
+            ]
+          },
+          "created": "2025-01-28T11:05:00Z",
+          "author": {
+            "name": "Developer",
+            "email": "dev@example.com"
+          }
+        }
+      ]
+    }
+  ]
+}
diff --git a/examples/semantic-document/content/document.json b/examples/semantic-document/content/document.json
new file mode 100644
index 0000000..ca85213
--- /dev/null
+++ b/examples/semantic-document/content/document.json
@@ -0,0 +1,184 @@
+{
+  "version": "0.1",
+  "blocks": [
+    {
+      "type": "heading",
+      "id": "title",
+      "level": 1,
+      "children": [
+        { "type": "text", "value": "The History of Computing" }
+      ]
+    },
+    {
+      "type": "paragraph",
+      "id": "intro",
+      "children": [
+        { "type": "text", "value": "The development of modern computing began with theoretical work by " },
+        {
+          "type": "text",
+          "value": "Alan Turing",
+          "marks": [
+            {
+              "type": "entity",
+              "uri": "https://www.wikidata.org/wiki/Q7251",
+              "entityType": "Person",
+              "source": "wikidata"
+            }
+          ]
+        },
+        { "type": "text", "value": " in the 1930s. His concept of the " },
+        {
+          "type": "text",
+          "value": "Turing machine",
+          "marks": [
+            { "type": "glossary", "ref": "turing-machine" }
+          ]
+        },
+        { "type": "text", "value": " laid the foundation for all modern computers" },
+        {
+          "type": "text",
+          "value": "[1]",
+          "marks": [
+            {
+              "type": "citation",
+              "refs": ["turing1936"],
+              "locator": "pp. 230-265"
+            }
+          ]
+        },
+        { "type": "text", "value": "." }
+      ]
+    },
+    {
+      "type": "paragraph",
+      "id": "para-2",
+      "children": [
+        { "type": "text", "value": "The first electronic general-purpose computer, " },
+        {
+          "type": "text",
+          "value": "ENIAC",
+          "marks": [
+            {
+              "type": "entity",
+              "uri": "https://www.wikidata.org/wiki/Q12637",
+              "entityType": "Product",
+              "source": "wikidata"
+            }
+          ]
+        },
+        { "type": "text", "value": ", was completed in 1945" },
+        {
+          "type": "text",
+          "value": "[2]",
+          "marks": [
+            { "type": "citation", "refs": ["goldstine1972"] }
+          ]
+        },
+        { "type": "text", "value": ". This marked the beginning of the digital age" },
+        {
+          "type": "text",
+          "value": "1",
+          "marks": [
+            { "type": "footnote", "number": 1, "id": "fn1" }
+          ]
+        },
+        { "type": "text", "value": "." }
+      ]
+    },
+    {
+      "type": "semantic:footnote",
+      "number": 1,
+      "id": "fn1",
+      "children": [
+        {
+          "type": "paragraph",
+          "children": [
+            { "type": "text", "value": "Some historians argue that earlier mechanical computers, such as Babbage's Analytical Engine, should be considered the true beginning of the computing era. See " },
+            {
+              "type": "text",
+              "value": "[3]",
+              "marks": [
+                { "type": "citation", "refs": ["swade2001"] }
+              ]
+            },
+            { "type": "text", "value": " for a detailed discussion." }
+          ]
+        }
+      ]
+    },
+    {
+      "type": "heading",
+      "id": "sec-algorithm",
+      "level": 2,
+      "children": [
+        { "type": "text", "value": "The Concept of an Algorithm" }
+      ]
+    },
+    {
+      "type": "paragraph",
+      "id": "para-3",
+      "children": [
+        { "type": "text", "value": "An " },
+        {
+          "type": "text",
+          "value": "algorithm",
+          "marks": [
+            { "type": "glossary", "ref": "algorithm" }
+          ]
+        },
+        { "type": "text", "value": " is a fundamental concept in computer science. Multiple researchers have contributed to its formalization, as noted by various scholars" },
+        {
+          "type": "text",
+          "value": "[1, 4]",
+          "marks": [
+            {
+              "type": "citation",
+              "refs": ["turing1936", "knuth1997"],
+              "prefix": "see"
+            }
+          ]
+        },
+        { "type": "text", "value": "." }
+      ]
+    },
+    {
+      "type": "semantic:term",
+      "id": "term-algorithm",
+      "term": "Algorithm",
+      "definition": "A finite sequence of well-defined instructions for solving a class of problems or performing a computation.",
+      "see": ["turing-machine"]
+    },
+    {
+      "type": "semantic:term",
+      "id": "term-turing-machine",
+      "term": "Turing Machine",
+      "definition": "A mathematical model of computation describing an abstract machine that manipulates symbols on a strip of tape according to a table of rules."
+    },
+    {
+      "type": "heading",
+      "id": "sec-glossary",
+      "level": 2,
+      "children": [
+        { "type": "text", "value": "Glossary" }
+      ]
+    },
+    {
+      "type": "semantic:glossary",
+      "title": "Terms",
+      "sort": "alphabetical"
+    },
+    {
+      "type": "heading",
+      "id": "sec-references",
+      "level": 2,
+      "children": [
+        { "type": "text", "value": "References" }
+      ]
+    },
+    {
+      "type": "semantic:bibliography",
+      "style": "apa",
+      "title": null
+    }
+  ]
+}
diff --git a/examples/semantic-document/manifest.json b/examples/semantic-document/manifest.json
new file mode 100644
index 0000000..d40048e
--- /dev/null
+++ b/examples/semantic-document/manifest.json
@@ -0,0 +1,25 @@
+{
+  "codex": "0.1",
+  "id": "pending",
+  "state": "draft",
+  "created": "2025-01-28T14:00:00Z",
+  "modified": "2025-01-28T14:00:00Z",
+  "extensions": [
+    {
+      "id": "codex.semantic",
+      "version": "0.1",
+      "required": false
+    }
+  ],
+  "content": {
+    "path": "content/document.json",
+    "hash": "sha256:e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855"
+  },
+  "metadata": {
+    "dublinCore": "metadata/dublin-core.json"
+  },
+  "semantic": {
+    "bibliography": "semantic/bibliography.json",
+    "glossary": "semantic/glossary.json"
+  }
+}
diff --git a/examples/semantic-document/metadata/dublin-core.json b/examples/semantic-document/metadata/dublin-core.json
new file mode 100644
index 0000000..090ea1b
--- /dev/null
+++ b/examples/semantic-document/metadata/dublin-core.json
@@ -0,0 +1,14 @@
+{
+  "version": "1.1",
+  "terms": {
+    "title": "The History of Computing",
+    "creator": "John Smith",
+    "subject": ["computer science", "history", "computing"],
+    "description": "A demonstration of semantic extension features including citations, footnotes, glossary terms, and entity annotations.",
+    "date": "2025-01-28",
+    "type": "Text",
+    "format": "application/vnd.codex+zip",
+    "language": "en",
+    "rights": "CC BY 4.0"
+  }
+}
diff --git a/examples/semantic-document/semantic/bibliography.json b/examples/semantic-document/semantic/bibliography.json
new file mode 100644
index 0000000..b1aa6b3
--- /dev/null
+++ b/examples/semantic-document/semantic/bibliography.json
@@ -0,0 +1,64 @@
+{
+  "version": "0.1",
+  "entries": [
+    {
+      "id": "turing1936",
+      "type": "article-journal",
+      "title": "On Computable Numbers, with an Application to the Entscheidungsproblem",
+      "author": [
+        { "family": "Turing", "given": "Alan M." }
+      ],
+      "issued": {
+        "date-parts": [[1936]]
+      },
+      "container-title": "Proceedings of the London Mathematical Society",
+      "volume": "42",
+      "issue": "1",
+      "page": "230-265",
+      "DOI": "10.1112/plms/s2-42.1.230"
+    },
+    {
+      "id": "goldstine1972",
+      "type": "book",
+      "title": "The Computer from Pascal to von Neumann",
+      "author": [
+        { "family": "Goldstine", "given": "Herman H." }
+      ],
+      "issued": {
+        "date-parts": [[1972]]
+      },
+      "publisher": "Princeton University Press",
+      "publisher-place": "Princeton, NJ",
+      "ISBN": "978-0691023670"
+    },
+    {
+      "id": "swade2001",
+      "type": "book",
+      "title": "The Difference Engine: Charles Babbage and the Quest to Build the First Computer",
+      "author": [
+        { "family": "Swade", "given": "Doron" }
+      ],
+      "issued": {
+        "date-parts": [[2001]]
+      },
+      "publisher": "Viking Press",
+      "publisher-place": "New York",
+      "ISBN": "978-0670910205"
+    },
+    {
+      "id": "knuth1997",
+      "type": "book",
+      "title": "The Art of Computer Programming, Volume 1: Fundamental Algorithms",
+      "author": [
+        { "family": "Knuth", "given": "Donald E." }
+      ],
+      "issued": {
+        "date-parts": [[1997]]
+      },
+      "edition": "3rd",
+      "publisher": "Addison-Wesley",
+      "publisher-place": "Reading, MA",
+      "ISBN": "978-0201896831"
+    }
+  ]
+}
diff --git a/examples/semantic-document/semantic/glossary.json b/examples/semantic-document/semantic/glossary.json
new file mode 100644
index 0000000..f829547
--- /dev/null
+++ b/examples/semantic-document/semantic/glossary.json
@@ -0,0 +1,16 @@
+{
+  "version": "0.1",
+  "terms": [
+    {
+      "id": "algorithm",
+      "term": "Algorithm",
+      "definition": "A finite sequence of well-defined instructions for solving a class of problems or performing a computation.",
+      "see": ["turing-machine"]
+    },
+    {
+      "id": "turing-machine",
+      "term": "Turing Machine",
+      "definition": "A mathematical model of computation describing an abstract machine that manipulates symbols on a strip of tape according to a table of rules."
+    }
+  ]
+}
diff --git a/schemas/README.md b/schemas/README.md
index eb7adf8..baab9fb 100644
--- a/schemas/README.md
+++ b/schemas/README.md
@@ -23,6 +23,9 @@ This directory contains JSON Schema definitions for validating Codex document co
 |--------|---------|-----------|
 | `semantic.schema.json` | Semantic extension | `semantic:*` blocks and marks |
 | `academic.schema.json` | Academic extension | `academic:*` blocks and marks |
+| `collaboration.schema.json` | Collaboration extension | `collaboration/comments.json`, `collaboration/changes.json` |
+| `forms.schema.json` | Forms extension | `forms/data.json`, `forms:*` blocks |
+| `security.schema.json` | Security extension | `security/signatures.json`, `security/encryption.json` |
 
 ## Schema Dependencies
 
@@ -32,11 +35,18 @@ Some schemas reference definitions from other schema files:
 annotations.schema.json
     └── $ref: anchor.schema.json#/$defs/contentAnchor
 
+collaboration.schema.json
+    └── $ref: anchor.schema.json#/$defs/contentAnchor
+
+content.schema.json
+    ├── $ref: semantic.schema.json#/$defs/*Mark
+    └── $ref: academic.schema.json#/$defs/*Mark
+
 phantoms.schema.json
     └── $ref: anchor.schema.json#/$defs/contentAnchor
 ```
 
-The `anchor.schema.json` file provides shared definitions for `ContentAnchor` and `ContentAnchorUri` that are used by core annotations, phantoms, collaboration, and other extensions.
+The `anchor.schema.json` file provides shared definitions for `ContentAnchor`, `ContentAnchorUri`, and `person` that are used by core annotations, phantoms, collaboration, and other extensions.
 
 ## Using These Schemas
 
@@ -100,3 +110,41 @@ All schemas are written for JSON Schema Draft 2020-12 (`https://json-schema.org/
 - Schemas use `additionalProperties: false` on most objects to catch typos and invalid properties
 - The `metadata` object in `phantoms.schema.json` intentionally allows additional properties for application-specific extensibility
 - The `styles` object in `presentation.schema.json` allows arbitrary named styles, but each style definition is strictly validated
+
+## Extension Policy
+
+### additionalProperties Defaults
+
+- **Default**: `additionalProperties: false` for strict validation
+- **Exceptions**:
+  - `metadata` objects allow custom properties (application extensibility)
+  - CSL bibliography entries allow additional fields (CSL spec compatibility)
+  - JSON-LD annotations allow arbitrary properties (linked data)
+  - Base Person object allows extension-specific fields via `allOf` composition
+
+### Shared Type Composition
+
+Extension schemas that need Person/author objects use `allOf` composition with the base definition from `anchor.schema.json`:
+
+```json
+{
+  "author": {
+    "allOf": [
+      { "$ref": "anchor.schema.json#/$defs/person" },
+      {
+        "type": "object",
+        "properties": {
+          "extensionSpecificField": { "type": "string" }
+        }
+      }
+    ]
+  }
+}
+```
+
+### Versioning
+
+- Extension READMEs declare version in header (e.g., `Version: 0.1`)
+- Data files include `version` field for file format versioning
+- Schema `$id` URIs don't include versions (versioned by spec release)
+- collaboration v0.2 is intentional (migration from v0.1 with `blockRef`/`range` to `anchor`)
diff --git a/schemas/anchor.schema.json b/schemas/anchor.schema.json
index 5d63673..68f3c01 100644
--- a/schemas/anchor.schema.json
+++ b/schemas/anchor.schema.json
@@ -1,9 +1,30 @@
 {
   "$schema": "https://json-schema.org/draft/2020-12/schema",
   "$id": "https://codex.document/schemas/anchor.schema.json",
-  "title": "Codex Content Anchor Definitions",
-  "description": "Reusable schema definitions for ContentAnchor and ContentAnchorUri, used by collaboration, phantoms, and other extensions.",
+  "title": "Codex Content Anchor and Person Definitions",
+  "description": "Reusable schema definitions for ContentAnchor, ContentAnchorUri, and Person, used by collaboration, phantoms, security, and other extensions.",
   "$defs": {
+    "person": {
+      "type": "object",
+      "description": "Base person/agent identity. Extensions may add additional properties via allOf composition.",
+      "required": ["name"],
+      "properties": {
+        "name": {
+          "type": "string",
+          "description": "Display name"
+        },
+        "email": {
+          "type": "string",
+          "format": "email",
+          "description": "Email address"
+        },
+        "identifier": {
+          "type": "string",
+          "description": "Persistent identifier (ORCID, DID, URL, institutional ID). For scholarly documents, ORCID format is recommended: https://orcid.org/0000-0002-1825-0097"
+        }
+      },
+      "additionalProperties": true
+    },
     "contentAnchor": {
       "type": "object",
       "description": "Structured content anchor referencing a block, point, or range within document content.",
diff --git a/schemas/collaboration.schema.json b/schemas/collaboration.schema.json
new file mode 100644
index 0000000..2e5afd2
--- /dev/null
+++ b/schemas/collaboration.schema.json
@@ -0,0 +1,341 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://codex.document/schemas/collaboration.schema.json",
+  "title": "Codex Collaboration Extension",
+  "description": "Schema for collaboration extension files in a Codex document",
+  "$defs": {
+    "crdtFormat": {
+      "type": "string",
+      "description": "CRDT library format for interoperability",
+      "enum": ["yjs", "automerge", "diamond-types", "custom"]
+    },
+    "author": {
+      "description": "Comment/change author information extending base person",
+      "allOf": [
+        { "$ref": "https://codex.document/schemas/anchor.schema.json#/$defs/person" },
+        {
+          "type": "object",
+          "properties": {
+            "userId": {
+              "type": "string",
+              "description": "User identifier in an external system"
+            },
+            "avatar": {
+              "type": "string",
+              "format": "uri",
+              "description": "URL to avatar image"
+            },
+            "color": {
+              "type": "string",
+              "description": "Color for real-time cursor/highlight display (CSS color value)"
+            }
+          }
+        }
+      ],
+      "unevaluatedProperties": false
+    },
+    "commentType": {
+      "type": "string",
+      "description": "Type of comment annotation",
+      "enum": ["comment", "highlight", "suggestion", "reaction"]
+    },
+    "suggestionStatus": {
+      "type": "string",
+      "description": "Status of a suggestion",
+      "enum": ["pending", "accepted", "rejected"]
+    },
+    "reply": {
+      "type": "object",
+      "description": "A reply to a comment",
+      "required": ["id", "author", "created", "content"],
+      "properties": {
+        "id": {
+          "type": "string",
+          "description": "Unique reply identifier"
+        },
+        "author": {
+          "$ref": "#/$defs/author"
+        },
+        "created": {
+          "type": "string",
+          "format": "date-time",
+          "description": "ISO 8601 creation timestamp"
+        },
+        "content": {
+          "type": "string",
+          "description": "Reply text content"
+        }
+      },
+      "additionalProperties": false
+    },
+    "baseComment": {
+      "type": "object",
+      "description": "Base comment properties shared by all comment types",
+      "required": ["id", "type", "anchor", "author", "created"],
+      "properties": {
+        "id": {
+          "type": "string",
+          "description": "Unique comment identifier"
+        },
+        "type": {
+          "$ref": "#/$defs/commentType"
+        },
+        "anchor": {
+          "$ref": "https://codex.document/schemas/anchor.schema.json#/$defs/contentAnchor",
+          "description": "Anchor to content (see Anchors and References spec)"
+        },
+        "author": {
+          "$ref": "#/$defs/author"
+        },
+        "created": {
+          "type": "string",
+          "format": "date-time",
+          "description": "ISO 8601 creation timestamp"
+        },
+        "modified": {
+          "type": "string",
+          "format": "date-time",
+          "description": "ISO 8601 last modification timestamp"
+        },
+        "resolved": {
+          "type": "boolean",
+          "description": "Whether the comment is resolved",
+          "default": false
+        },
+        "replies": {
+          "type": "array",
+          "description": "Reply comments",
+          "items": {
+            "$ref": "#/$defs/reply"
+          }
+        }
+      }
+    },
+    "comment": {
+      "allOf": [
+        { "$ref": "#/$defs/baseComment" },
+        {
+          "type": "object",
+          "required": ["content"],
+          "properties": {
+            "type": { "const": "comment" },
+            "content": {
+              "type": "string",
+              "description": "Comment text content"
+            }
+          }
+        }
+      ]
+    },
+    "highlight": {
+      "allOf": [
+        { "$ref": "#/$defs/baseComment" },
+        {
+          "type": "object",
+          "properties": {
+            "type": { "const": "highlight" },
+            "content": {
+              "type": "string",
+              "description": "Optional note for the highlight"
+            }
+          }
+        }
+      ]
+    },
+    "suggestion": {
+      "allOf": [
+        { "$ref": "#/$defs/baseComment" },
+        {
+          "type": "object",
+          "required": ["originalText", "suggestedText"],
+          "properties": {
+            "type": { "const": "suggestion" },
+            "originalText": {
+              "type": "string",
+              "description": "Original text being replaced"
+            },
+            "suggestedText": {
+              "type": "string",
+              "description": "Suggested replacement text"
+            },
+            "status": {
+              "$ref": "#/$defs/suggestionStatus",
+              "default": "pending"
+            }
+          }
+        }
+      ]
+    },
+    "reaction": {
+      "allOf": [
+        { "$ref": "#/$defs/baseComment" },
+        {
+          "type": "object",
+          "required": ["emoji"],
+          "properties": {
+            "type": { "const": "reaction" },
+            "emoji": {
+              "type": "string",
+              "description": "Unicode CLDR short name (e.g., 'thumbsup', 'heart')"
+            }
+          }
+        }
+      ]
+    },
+    "commentEntry": {
+      "oneOf": [
+        { "$ref": "#/$defs/comment" },
+        { "$ref": "#/$defs/highlight" },
+        { "$ref": "#/$defs/suggestion" },
+        { "$ref": "#/$defs/reaction" }
+      ]
+    },
+    "changeType": {
+      "type": "string",
+      "description": "Type of tracked change",
+      "enum": ["insert", "delete", "modify", "move", "format"]
+    },
+    "changeStatus": {
+      "type": "string",
+      "description": "Status of a tracked change",
+      "enum": ["pending", "accepted", "rejected"]
+    },
+    "changePosition": {
+      "type": "object",
+      "description": "Position for inserted/moved blocks",
+      "properties": {
+        "after": {
+          "type": "string",
+          "description": "Block ID to insert after"
+        },
+        "before": {
+          "type": "string",
+          "description": "Block ID to insert before"
+        }
+      },
+      "additionalProperties": false
+    },
+    "change": {
+      "type": "object",
+      "description": "A tracked change record",
+      "required": ["id", "type", "anchor", "author", "timestamp"],
+      "properties": {
+        "id": {
+          "type": "string",
+          "description": "Unique change identifier"
+        },
+        "type": {
+          "$ref": "#/$defs/changeType"
+        },
+        "anchor": {
+          "$ref": "https://codex.document/schemas/anchor.schema.json#/$defs/contentAnchor",
+          "description": "Anchor to affected content"
+        },
+        "position": {
+          "$ref": "#/$defs/changePosition",
+          "description": "Position for insert/move operations"
+        },
+        "before": {
+          "type": "object",
+          "description": "Content state before the change (for modify/delete)"
+        },
+        "after": {
+          "type": "object",
+          "description": "Content state after the change (for modify/insert)"
+        },
+        "author": {
+          "$ref": "#/$defs/author"
+        },
+        "timestamp": {
+          "type": "string",
+          "format": "date-time",
+          "description": "ISO 8601 change timestamp"
+        },
+        "status": {
+          "$ref": "#/$defs/changeStatus",
+          "default": "pending"
+        }
+      },
+      "additionalProperties": false
+    },
+    "crdtMetadata": {
+      "type": "object",
+      "description": "CRDT metadata for block-level synchronization",
+      "properties": {
+        "clock": {
+          "type": "object",
+          "description": "Vector clock for causal ordering",
+          "additionalProperties": {
+            "type": "integer"
+          }
+        },
+        "origin": {
+          "type": "string",
+          "description": "Site/peer ID where this version originated"
+        },
+        "seq": {
+          "type": "integer",
+          "description": "Local sequence number"
+        }
+      },
+      "additionalProperties": false
+    },
+    "commentsFile": {
+      "type": "object",
+      "description": "Schema for collaboration/comments.json",
+      "required": ["version", "comments"],
+      "properties": {
+        "version": {
+          "type": "string",
+          "description": "Collaboration extension version",
+          "pattern": "^\\d+\\.\\d+$"
+        },
+        "crdtFormat": {
+          "$ref": "#/$defs/crdtFormat",
+          "description": "CRDT library format hint for interoperability"
+        },
+        "comments": {
+          "type": "array",
+          "description": "Array of comment entries",
+          "items": {
+            "$ref": "#/$defs/commentEntry"
+          }
+        }
+      },
+      "additionalProperties": false
+    },
+    "changesFile": {
+      "type": "object",
+      "description": "Schema for collaboration/changes.json",
+      "required": ["version", "changes"],
+      "properties": {
+        "version": {
+          "type": "string",
+          "description": "Collaboration extension version",
+          "pattern": "^\\d+\\.\\d+$"
+        },
+        "baseVersion": {
+          "type": "string",
+          "description": "Document ID (hash) of the base version",
+          "pattern": "^(sha256|sha384|sha512|sha3-256|sha3-512|blake3):[a-f0-9]+$"
+        },
+        "crdtFormat": {
+          "$ref": "#/$defs/crdtFormat",
+          "description": "CRDT library format hint for interoperability"
+        },
+        "changes": {
+          "type": "array",
+          "description": "Array of tracked changes",
+          "items": {
+            "$ref": "#/$defs/change"
+          }
+        }
+      },
+      "additionalProperties": false
+    }
+  },
+  "oneOf": [
+    { "$ref": "#/$defs/commentsFile" },
+    { "$ref": "#/$defs/changesFile" }
+  ]
+}
diff --git a/schemas/content.schema.json b/schemas/content.schema.json
index d94de0a..63e613a 100644
--- a/schemas/content.schema.json
+++ b/schemas/content.schema.json
@@ -171,7 +171,14 @@
               },
               { "$ref": "#/$defs/linkMark" },
               { "$ref": "#/$defs/anchorMark" },
-              { "$ref": "#/$defs/mathMark" }
+              { "$ref": "#/$defs/mathMark" },
+              { "$ref": "https://codex.document/schemas/semantic.schema.json#/$defs/citationMark" },
+              { "$ref": "https://codex.document/schemas/semantic.schema.json#/$defs/footnoteMark" },
+              { "$ref": "https://codex.document/schemas/semantic.schema.json#/$defs/entityMark" },
+              { "$ref": "https://codex.document/schemas/semantic.schema.json#/$defs/glossaryMark" },
+              { "$ref": "https://codex.document/schemas/academic.schema.json#/$defs/theoremRefMark" },
+              { "$ref": "https://codex.document/schemas/academic.schema.json#/$defs/equationRefMark" },
+              { "$ref": "https://codex.document/schemas/academic.schema.json#/$defs/algorithmRefMark" }
             ]
           }
         }
diff --git a/schemas/forms.schema.json b/schemas/forms.schema.json
new file mode 100644
index 0000000..2fe5f62
--- /dev/null
+++ b/schemas/forms.schema.json
@@ -0,0 +1,487 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://codex.document/schemas/forms.schema.json",
+  "title": "Codex Forms Extension",
+  "description": "Schema for forms extension blocks and data files in a Codex document",
+  "$defs": {
+    "validatorType": {
+      "type": "string",
+      "description": "Built-in validator types",
+      "enum": [
+        "required",
+        "minLength",
+        "maxLength",
+        "min",
+        "max",
+        "pattern",
+        "email",
+        "url",
+        "containsUppercase",
+        "containsLowercase",
+        "containsDigit",
+        "containsSpecial",
+        "matchesField"
+      ]
+    },
+    "validation": {
+      "type": "object",
+      "description": "Validation rules for a form field",
+      "properties": {
+        "required": {
+          "type": "boolean",
+          "description": "Field must have a value"
+        },
+        "minLength": {
+          "type": "integer",
+          "minimum": 0,
+          "description": "Minimum string length"
+        },
+        "maxLength": {
+          "type": "integer",
+          "minimum": 0,
+          "description": "Maximum string length"
+        },
+        "min": {
+          "type": "number",
+          "description": "Minimum numeric value"
+        },
+        "max": {
+          "type": "number",
+          "description": "Maximum numeric value"
+        },
+        "pattern": {
+          "type": "string",
+          "description": "Regular expression pattern to match"
+        },
+        "email": {
+          "type": "boolean",
+          "description": "Must be a valid email format"
+        },
+        "url": {
+          "type": "boolean",
+          "description": "Must be a valid URL format"
+        },
+        "containsUppercase": {
+          "type": "boolean",
+          "description": "Must contain at least one uppercase letter"
+        },
+        "containsLowercase": {
+          "type": "boolean",
+          "description": "Must contain at least one lowercase letter"
+        },
+        "containsDigit": {
+          "type": "boolean",
+          "description": "Must contain at least one digit"
+        },
+        "containsSpecial": {
+          "type": "boolean",
+          "description": "Must contain at least one special character"
+        },
+        "matchesField": {
+          "type": "string",
+          "description": "Must match the value of another named field"
+        },
+        "message": {
+          "type": "string",
+          "description": "Custom error message for validation failure"
+        }
+      },
+      "additionalProperties": false
+    },
+    "conditionalValidation": {
+      "type": "object",
+      "description": "Conditional validation rules based on other field values",
+      "required": ["when", "then"],
+      "properties": {
+        "when": {
+          "type": "object",
+          "description": "Condition to evaluate",
+          "required": ["field"],
+          "properties": {
+            "field": {
+              "type": "string",
+              "description": "Name of the field to check"
+            },
+            "equals": {
+              "description": "Condition is true when field equals this value"
+            },
+            "notEquals": {
+              "description": "Condition is true when field does not equal this value"
+            },
+            "isEmpty": {
+              "type": "boolean",
+              "description": "Condition is true when field is empty"
+            },
+            "isNotEmpty": {
+              "type": "boolean",
+              "description": "Condition is true when field is not empty"
+            }
+          },
+          "additionalProperties": false
+        },
+        "then": {
+          "$ref": "#/$defs/validation",
+          "description": "Validation rules to apply when condition is met"
+        }
+      },
+      "additionalProperties": false
+    },
+    "option": {
+      "type": "object",
+      "description": "Option for dropdown, radio group, or checkbox group",
+      "required": ["value", "label"],
+      "properties": {
+        "value": {
+          "type": "string",
+          "description": "Option value"
+        },
+        "label": {
+          "type": "string",
+          "description": "Display label"
+        },
+        "disabled": {
+          "type": "boolean",
+          "description": "Whether option is disabled",
+          "default": false
+        }
+      },
+      "additionalProperties": false
+    },
+    "fallbackBlock": {
+      "type": "object",
+      "description": "Fallback content for viewers that don't support forms",
+      "required": ["type"],
+      "properties": {
+        "type": {
+          "type": "string",
+          "description": "Block type (typically 'paragraph')"
+        },
+        "children": {
+          "type": "array",
+          "description": "Child content"
+        }
+      }
+    },
+    "baseFormField": {
+      "type": "object",
+      "description": "Base properties shared by all form fields",
+      "properties": {
+        "id": {
+          "type": "string",
+          "description": "Unique block identifier"
+        },
+        "name": {
+          "type": "string",
+          "description": "Field name for form data"
+        },
+        "label": {
+          "type": "string",
+          "description": "Display label"
+        },
+        "placeholder": {
+          "type": "string",
+          "description": "Placeholder text"
+        },
+        "required": {
+          "type": "boolean",
+          "description": "Whether field is required",
+          "default": false
+        },
+        "disabled": {
+          "type": "boolean",
+          "description": "Whether field is disabled",
+          "default": false
+        },
+        "validation": {
+          "$ref": "#/$defs/validation"
+        },
+        "conditionalValidation": {
+          "$ref": "#/$defs/conditionalValidation"
+        },
+        "fallback": {
+          "$ref": "#/$defs/fallbackBlock"
+        }
+      }
+    },
+    "formContainer": {
+      "type": "object",
+      "description": "Form container block",
+      "required": ["type", "children"],
+      "properties": {
+        "type": { "const": "forms:form" },
+        "id": {
+          "type": "string",
+          "description": "Unique form identifier"
+        },
+        "action": {
+          "type": "string",
+          "format": "uri",
+          "description": "Form submission URL"
+        },
+        "method": {
+          "type": "string",
+          "enum": ["GET", "POST"],
+          "description": "HTTP method for submission",
+          "default": "POST"
+        },
+        "encoding": {
+          "type": "string",
+          "description": "Form encoding type",
+          "default": "application/json"
+        },
+        "children": {
+          "type": "array",
+          "description": "Form field blocks"
+        }
+      },
+      "additionalProperties": false
+    },
+    "textInputBlock": {
+      "allOf": [
+        { "$ref": "#/$defs/baseFormField" },
+        {
+          "type": "object",
+          "required": ["type", "name"],
+          "properties": {
+            "type": { "const": "forms:textInput" },
+            "inputType": {
+              "type": "string",
+              "enum": ["text", "email", "password", "tel", "number"],
+              "description": "HTML input type",
+              "default": "text"
+            },
+            "maxLength": {
+              "type": "integer",
+              "minimum": 1,
+              "description": "Maximum character length"
+            },
+            "autocomplete": {
+              "type": "string",
+              "description": "Autocomplete hint"
+            }
+          },
+          "additionalProperties": false
+        }
+      ]
+    },
+    "textAreaBlock": {
+      "allOf": [
+        { "$ref": "#/$defs/baseFormField" },
+        {
+          "type": "object",
+          "required": ["type", "name"],
+          "properties": {
+            "type": { "const": "forms:textArea" },
+            "rows": {
+              "type": "integer",
+              "minimum": 1,
+              "description": "Number of visible text rows",
+              "default": 4
+            },
+            "maxLength": {
+              "type": "integer",
+              "minimum": 1,
+              "description": "Maximum character length"
+            }
+          },
+          "additionalProperties": false
+        }
+      ]
+    },
+    "checkboxBlock": {
+      "allOf": [
+        { "$ref": "#/$defs/baseFormField" },
+        {
+          "type": "object",
+          "required": ["type", "name"],
+          "properties": {
+            "type": { "const": "forms:checkbox" },
+            "defaultChecked": {
+              "type": "boolean",
+              "description": "Initial checked state",
+              "default": false
+            }
+          },
+          "additionalProperties": false
+        }
+      ]
+    },
+    "radioGroupBlock": {
+      "allOf": [
+        { "$ref": "#/$defs/baseFormField" },
+        {
+          "type": "object",
+          "required": ["type", "name", "options"],
+          "properties": {
+            "type": { "const": "forms:radioGroup" },
+            "options": {
+              "type": "array",
+              "description": "Radio button options",
+              "items": { "$ref": "#/$defs/option" },
+              "minItems": 1
+            },
+            "defaultValue": {
+              "type": "string",
+              "description": "Default selected value"
+            }
+          },
+          "additionalProperties": false
+        }
+      ]
+    },
+    "dropdownBlock": {
+      "allOf": [
+        { "$ref": "#/$defs/baseFormField" },
+        {
+          "type": "object",
+          "required": ["type", "name", "options"],
+          "properties": {
+            "type": { "const": "forms:dropdown" },
+            "options": {
+              "type": "array",
+              "description": "Dropdown options",
+              "items": { "$ref": "#/$defs/option" },
+              "minItems": 1
+            },
+            "defaultValue": {
+              "type": "string",
+              "description": "Default selected value"
+            },
+            "searchable": {
+              "type": "boolean",
+              "description": "Enable search/filter functionality",
+              "default": false
+            },
+            "multiple": {
+              "type": "boolean",
+              "description": "Allow multiple selections",
+              "default": false
+            }
+          },
+          "additionalProperties": false
+        }
+      ]
+    },
+    "datePickerBlock": {
+      "allOf": [
+        { "$ref": "#/$defs/baseFormField" },
+        {
+          "type": "object",
+          "required": ["type", "name"],
+          "properties": {
+            "type": { "const": "forms:datePicker" },
+            "format": {
+              "type": "string",
+              "description": "Date format pattern (e.g., 'YYYY-MM-DD')",
+              "default": "YYYY-MM-DD"
+            },
+            "minDate": {
+              "type": "string",
+              "description": "Minimum selectable date (ISO date or 'today')"
+            },
+            "maxDate": {
+              "type": "string",
+              "description": "Maximum selectable date (ISO date or 'today')"
+            },
+            "includeTime": {
+              "type": "boolean",
+              "description": "Include time selection",
+              "default": false
+            }
+          },
+          "additionalProperties": false
+        }
+      ]
+    },
+    "signatureBlock": {
+      "allOf": [
+        { "$ref": "#/$defs/baseFormField" },
+        {
+          "type": "object",
+          "required": ["type", "name"],
+          "properties": {
+            "type": { "const": "forms:signature" },
+            "width": {
+              "type": "integer",
+              "minimum": 100,
+              "description": "Signature pad width in pixels"
+            },
+            "height": {
+              "type": "integer",
+              "minimum": 50,
+              "description": "Signature pad height in pixels"
+            }
+          },
+          "additionalProperties": false
+        }
+      ]
+    },
+    "submitBlock": {
+      "type": "object",
+      "description": "Form submit button",
+      "required": ["type"],
+      "properties": {
+        "type": { "const": "forms:submit" },
+        "id": {
+          "type": "string",
+          "description": "Unique block identifier"
+        },
+        "label": {
+          "type": "string",
+          "description": "Button label",
+          "default": "Submit"
+        }
+      },
+      "additionalProperties": false
+    },
+    "formBlock": {
+      "oneOf": [
+        { "$ref": "#/$defs/formContainer" },
+        { "$ref": "#/$defs/textInputBlock" },
+        { "$ref": "#/$defs/textAreaBlock" },
+        { "$ref": "#/$defs/checkboxBlock" },
+        { "$ref": "#/$defs/radioGroupBlock" },
+        { "$ref": "#/$defs/dropdownBlock" },
+        { "$ref": "#/$defs/datePickerBlock" },
+        { "$ref": "#/$defs/signatureBlock" },
+        { "$ref": "#/$defs/submitBlock" }
+      ]
+    },
+    "dataFile": {
+      "type": "object",
+      "description": "Schema for forms/data.json",
+      "required": ["version", "values"],
+      "properties": {
+        "version": {
+          "type": "string",
+          "description": "Forms extension version",
+          "pattern": "^\\d+\\.\\d+$"
+        },
+        "values": {
+          "type": "object",
+          "description": "Map of field names to values",
+          "additionalProperties": true
+        },
+        "submitted": {
+          "type": "boolean",
+          "description": "Whether the form has been submitted",
+          "default": false
+        },
+        "submittedAt": {
+          "type": "string",
+          "format": "date-time",
+          "description": "ISO 8601 submission timestamp"
+        },
+        "lastModified": {
+          "type": "string",
+          "format": "date-time",
+          "description": "ISO 8601 last modification timestamp"
+        }
+      },
+      "additionalProperties": false
+    }
+  },
+  "type": "object",
+  "description": "Forms data file",
+  "$ref": "#/$defs/dataFile"
+}
diff --git a/schemas/phantoms.schema.json b/schemas/phantoms.schema.json
index 6bc5c1d..db01f93 100644
--- a/schemas/phantoms.schema.json
+++ b/schemas/phantoms.schema.json
@@ -187,20 +187,11 @@
       "additionalProperties": false
     },
     "author": {
-      "type": "object",
-      "required": ["name"],
-      "properties": {
-        "name": {
-          "type": "string",
-          "description": "Author display name"
-        },
-        "email": {
-          "type": "string",
-          "format": "email",
-          "description": "Author email address"
-        }
-      },
-      "additionalProperties": false
+      "description": "Author identity extending base person",
+      "allOf": [
+        { "$ref": "https://codex.document/schemas/anchor.schema.json#/$defs/person" }
+      ],
+      "unevaluatedProperties": false
     }
   }
 }
diff --git a/schemas/security.schema.json b/schemas/security.schema.json
new file mode 100644
index 0000000..9e442c6
--- /dev/null
+++ b/schemas/security.schema.json
@@ -0,0 +1,389 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://codex.document/schemas/security.schema.json",
+  "title": "Codex Security Extension",
+  "description": "Schema for security extension files in a Codex document",
+  "$defs": {
+    "signatureAlgorithm": {
+      "type": "string",
+      "description": "Supported signature algorithms",
+      "enum": ["ES256", "ES384", "EdDSA", "PS256", "ML-DSA-65"]
+    },
+    "algorithmStatus": {
+      "type": "object",
+      "description": "Algorithm status metadata for implementation guidance",
+      "properties": {
+        "ES256": {
+          "type": "object",
+          "properties": {
+            "status": { "const": "required" },
+            "description": { "type": "string" }
+          }
+        },
+        "ES384": {
+          "type": "object",
+          "properties": {
+            "status": { "const": "recommended" },
+            "description": { "type": "string" }
+          }
+        },
+        "EdDSA": {
+          "type": "object",
+          "properties": {
+            "status": { "const": "recommended" },
+            "description": { "type": "string" }
+          }
+        },
+        "PS256": {
+          "type": "object",
+          "properties": {
+            "status": { "const": "optional" },
+            "description": { "type": "string" }
+          }
+        },
+        "ML-DSA-65": {
+          "type": "object",
+          "properties": {
+            "status": { "const": "experimental" },
+            "note": { "type": "string" },
+            "description": { "type": "string" }
+          }
+        }
+      },
+      "additionalProperties": false
+    },
+    "contentEncryptionAlgorithm": {
+      "type": "string",
+      "description": "Content encryption algorithms",
+      "enum": ["A256GCM", "C20P"]
+    },
+    "keyManagementAlgorithm": {
+      "type": "string",
+      "description": "Key wrapping/management algorithms",
+      "enum": ["ECDH-ES+A256KW", "RSA-OAEP-256", "PBES2-HS256+A256KW"]
+    },
+    "signatureState": {
+      "type": "string",
+      "description": "Signature verification state",
+      "enum": ["valid", "invalid", "expired", "revoked", "untrusted", "unknown"]
+    },
+    "signer": {
+      "description": "Signer identity information extending base person",
+      "allOf": [
+        { "$ref": "https://codex.document/schemas/anchor.schema.json#/$defs/person" },
+        {
+          "type": "object",
+          "properties": {
+            "organization": {
+              "type": "string",
+              "description": "Signer's organization"
+            },
+            "certificate": {
+              "type": "string",
+              "description": "X.509 certificate in PEM format"
+            },
+            "keyId": {
+              "type": "string",
+              "description": "Key identifier (DID, URL, or other identifier)"
+            }
+          }
+        }
+      ],
+      "unevaluatedProperties": false
+    },
+    "trustedTimestamp": {
+      "type": "object",
+      "description": "Trusted timestamp from a timestamping authority",
+      "required": ["authority", "time", "token"],
+      "properties": {
+        "authority": {
+          "type": "string",
+          "format": "uri",
+          "description": "Timestamp authority URL"
+        },
+        "time": {
+          "type": "string",
+          "format": "date-time",
+          "description": "ISO 8601 timestamp from the authority"
+        },
+        "token": {
+          "type": "string",
+          "description": "Base64-encoded timestamp token"
+        },
+        "algorithm": {
+          "type": "string",
+          "description": "Hash algorithm used for timestamping",
+          "enum": ["SHA256", "SHA384", "SHA512"]
+        }
+      },
+      "additionalProperties": false
+    },
+    "signatureScope": {
+      "type": "object",
+      "description": "Scoped signature covering content and optional layouts",
+      "required": ["documentId"],
+      "properties": {
+        "documentId": {
+          "type": "string",
+          "description": "Content hash (must match top-level documentId)",
+          "pattern": "^(sha256|sha384|sha512|sha3-256|sha3-512|blake3):[a-f0-9]+$"
+        },
+        "layouts": {
+          "type": "object",
+          "description": "Map of layout path to layout file hash for visual attestation",
+          "additionalProperties": {
+            "type": "string",
+            "pattern": "^(sha256|sha384|sha512|sha3-256|sha3-512|blake3):[a-f0-9]+$"
+          }
+        }
+      },
+      "additionalProperties": true
+    },
+    "webauthnSignature": {
+      "type": "object",
+      "description": "WebAuthn/FIDO2 signature data",
+      "required": ["credentialId", "authenticatorData", "clientDataJSON", "signature"],
+      "properties": {
+        "credentialId": {
+          "type": "string",
+          "description": "Base64-encoded credential ID"
+        },
+        "authenticatorData": {
+          "type": "string",
+          "description": "Base64-encoded authenticator data"
+        },
+        "clientDataJSON": {
+          "type": "string",
+          "description": "Base64-encoded client data JSON"
+        },
+        "signature": {
+          "type": "string",
+          "description": "Base64-encoded signature"
+        }
+      },
+      "additionalProperties": false
+    },
+    "signature": {
+      "type": "object",
+      "description": "A digital signature entry",
+      "required": ["id", "algorithm", "signedAt", "signer", "value"],
+      "properties": {
+        "id": {
+          "type": "string",
+          "description": "Unique signature identifier"
+        },
+        "algorithm": {
+          "$ref": "#/$defs/signatureAlgorithm"
+        },
+        "signedAt": {
+          "type": "string",
+          "format": "date-time",
+          "description": "ISO 8601 signing timestamp"
+        },
+        "signer": {
+          "$ref": "#/$defs/signer"
+        },
+        "value": {
+          "type": "string",
+          "description": "Base64-encoded signature value"
+        },
+        "certificateChain": {
+          "type": "array",
+          "description": "Certificate chain for validation",
+          "items": {
+            "type": "string",
+            "description": "X.509 certificate in PEM format"
+          }
+        },
+        "timestamp": {
+          "$ref": "#/$defs/trustedTimestamp"
+        },
+        "scope": {
+          "$ref": "#/$defs/signatureScope",
+          "description": "Scoped signature attestation (content + layout)"
+        },
+        "webauthn": {
+          "$ref": "#/$defs/webauthnSignature",
+          "description": "WebAuthn signature data (alternative to value)"
+        }
+      },
+      "additionalProperties": false
+    },
+    "signaturesFile": {
+      "type": "object",
+      "description": "Schema for security/signatures.json",
+      "required": ["version", "documentId", "signatures"],
+      "properties": {
+        "version": {
+          "type": "string",
+          "description": "Security extension version",
+          "pattern": "^\\d+\\.\\d+$"
+        },
+        "documentId": {
+          "type": "string",
+          "description": "Document content hash being signed",
+          "pattern": "^(sha256|sha384|sha512|sha3-256|sha3-512|blake3):[a-f0-9]+$"
+        },
+        "signatures": {
+          "type": "array",
+          "description": "Array of signatures",
+          "items": {
+            "$ref": "#/$defs/signature"
+          }
+        }
+      },
+      "additionalProperties": false
+    },
+    "encryptionRecipient": {
+      "type": "object",
+      "description": "Encryption recipient with wrapped key",
+      "required": ["id", "encryptedKey"],
+      "properties": {
+        "id": {
+          "type": "string",
+          "description": "Recipient identifier"
+        },
+        "name": {
+          "type": "string",
+          "description": "Recipient display name"
+        },
+        "keyId": {
+          "type": "string",
+          "description": "Recipient's public key identifier"
+        },
+        "encryptedKey": {
+          "type": "string",
+          "description": "Base64-encoded encrypted content encryption key"
+        },
+        "ephemeralPublicKey": {
+          "type": "string",
+          "description": "Base64-encoded ephemeral public key (for ECDH)"
+        }
+      },
+      "additionalProperties": false
+    },
+    "encryptedContent": {
+      "type": "object",
+      "description": "Encrypted content reference",
+      "required": ["iv", "tag", "path"],
+      "properties": {
+        "iv": {
+          "type": "string",
+          "description": "Base64-encoded initialization vector"
+        },
+        "tag": {
+          "type": "string",
+          "description": "Base64-encoded authentication tag"
+        },
+        "path": {
+          "type": "string",
+          "description": "Path to encrypted file (typically with .enc suffix)"
+        }
+      },
+      "additionalProperties": false
+    },
+    "encryptionFile": {
+      "type": "object",
+      "description": "Schema for security/encryption.json",
+      "required": ["version", "algorithm", "keyManagement", "recipients", "encryptedContent"],
+      "properties": {
+        "version": {
+          "type": "string",
+          "description": "Security extension version",
+          "pattern": "^\\d+\\.\\d+$"
+        },
+        "algorithm": {
+          "$ref": "#/$defs/contentEncryptionAlgorithm"
+        },
+        "keyManagement": {
+          "$ref": "#/$defs/keyManagementAlgorithm"
+        },
+        "recipients": {
+          "type": "array",
+          "description": "Array of recipients who can decrypt",
+          "items": {
+            "$ref": "#/$defs/encryptionRecipient"
+          },
+          "minItems": 1
+        },
+        "encryptedContent": {
+          "$ref": "#/$defs/encryptedContent"
+        }
+      },
+      "additionalProperties": false
+    },
+    "permission": {
+      "type": "object",
+      "description": "Permission grants",
+      "properties": {
+        "view": {
+          "type": "boolean",
+          "description": "Can view document content"
+        },
+        "print": {
+          "type": "boolean",
+          "description": "Can print document"
+        },
+        "copy": {
+          "type": "boolean",
+          "description": "Can copy text to clipboard"
+        },
+        "annotate": {
+          "type": "boolean",
+          "description": "Can add comments/annotations"
+        },
+        "edit": {
+          "type": "boolean",
+          "description": "Can edit content (draft only)"
+        },
+        "sign": {
+          "type": "boolean",
+          "description": "Can add signatures"
+        },
+        "decrypt": {
+          "type": "boolean",
+          "description": "Can decrypt if encrypted"
+        }
+      },
+      "additionalProperties": false
+    },
+    "principalPermission": {
+      "type": "object",
+      "description": "Permission assignment to a principal",
+      "required": ["principal", "grants"],
+      "properties": {
+        "principal": {
+          "type": "string",
+          "description": "Principal identifier (user:email, group:name, role:name, or *)",
+          "pattern": "^(user:[^:]+|group:[^:]+|role:[^:]+|\\*)$"
+        },
+        "grants": {
+          "$ref": "#/$defs/permission"
+        }
+      },
+      "additionalProperties": false
+    },
+    "accessControl": {
+      "type": "object",
+      "description": "Access control configuration",
+      "properties": {
+        "default": {
+          "$ref": "#/$defs/permission",
+          "description": "Default permissions for unauthenticated users"
+        },
+        "permissions": {
+          "type": "array",
+          "description": "Permission assignments to principals",
+          "items": {
+            "$ref": "#/$defs/principalPermission"
+          }
+        }
+      },
+      "additionalProperties": false
+    }
+  },
+  "oneOf": [
+    { "$ref": "#/$defs/signaturesFile" },
+    { "$ref": "#/$defs/encryptionFile" }
+  ]
+}
diff --git a/scripts/validate-examples.ts b/scripts/validate-examples.ts
index e71056a..b1ec768 100644
--- a/scripts/validate-examples.ts
+++ b/scripts/validate-examples.ts
@@ -40,22 +40,44 @@ function loadJson(filepath: string): unknown {
   return JSON.parse(content);
 }
 
+// Schema dependencies (schemas that need other schemas loaded first)
+const schemaDependencies: Record<string, string[]> = {
+  'content.schema.json': ['semantic.schema.json', 'academic.schema.json'],
+  'collaboration.schema.json': ['anchor.schema.json'],
+  'phantoms.schema.json': ['anchor.schema.json'],
+  'security.schema.json': ['anchor.schema.json'],
+};
+
 function getValidator(schemaName: string): ValidateFunction {
   if (!validators[schemaName]) {
     const ajv = createAjv();
+    // Load dependency schemas first
+    const deps = schemaDependencies[schemaName] || [];
+    for (const dep of deps) {
+      const depSchema = loadSchema(dep);
+      ajv.addSchema(depSchema);
+    }
     const schema = loadSchema(schemaName);
     validators[schemaName] = ajv.compile(schema);
   }
   return validators[schemaName];
 }
 
-// Document validations to perform
+// Document validations to perform (common files)
 const validations: Validation[] = [
   { schema: 'manifest.schema.json', file: 'manifest.json' },
   { schema: 'content.schema.json', file: 'content/document.json' },
   { schema: 'dublin-core.schema.json', file: 'metadata/dublin-core.json' },
 ];
 
+// Extension-specific validations (only if files exist)
+const extensionValidations: Validation[] = [
+  { schema: 'collaboration.schema.json', file: 'collaboration/comments.json' },
+  { schema: 'collaboration.schema.json', file: 'collaboration/changes.json' },
+  { schema: 'forms.schema.json', file: 'forms/data.json' },
+  { schema: 'phantoms.schema.json', file: 'phantoms/clusters.json' },
+];
+
 let hasErrors = false;
 
 console.log('Validating example documents...\n');
@@ -69,6 +91,7 @@ for (const exampleName of exampleDirs) {
   console.log(`${exampleName}/`);
   const examplePath = path.join(examplesDir, exampleName);
 
+  // Validate common files
   for (const { schema, file } of validations) {
     const filepath = path.join(examplePath, file);
 
@@ -97,6 +120,35 @@ for (const exampleName of exampleDirs) {
       hasErrors = true;
     }
   }
+
+  // Validate extension-specific files (silently skip if not present)
+  for (const { schema, file } of extensionValidations) {
+    const filepath = path.join(examplePath, file);
+
+    if (!fs.existsSync(filepath)) {
+      continue;
+    }
+
+    try {
+      const validate = getValidator(schema);
+      const data = loadJson(filepath);
+      const valid = validate(data);
+
+      if (valid) {
+        console.log(`  ✓ ${file}`);
+      } else {
+        console.log(`  ✗ ${file}`);
+        for (const err of validate.errors ?? []) {
+          console.log(`    - ${err.instancePath || '/'}: ${err.message}`);
+        }
+        hasErrors = true;
+      }
+    } catch (err) {
+      console.log(`  ✗ ${file}`);
+      console.log(`    Error: ${err instanceof Error ? err.message : String(err)}`);
+      hasErrors = true;
+    }
+  }
   console.log('');
 }
 
diff --git a/scripts/validate-schemas.ts b/scripts/validate-schemas.ts
index b9662fd..a000737 100644
--- a/scripts/validate-schemas.ts
+++ b/scripts/validate-schemas.ts
@@ -21,8 +21,8 @@ const standaloneSchemas: string[] = [
   'academic.schema.json',
   'anchor.schema.json',
   'asset-index.schema.json',
-  'content.schema.json',
   'dublin-core.schema.json',
+  'forms.schema.json',
   'manifest.schema.json',
   'precise-layout.schema.json',
   'presentation.schema.json',
@@ -33,7 +33,10 @@ const standaloneSchemas: string[] = [
 // Schemas that reference other schemas
 const dependentSchemas: DependentSchema[] = [
   { schema: 'annotations.schema.json', refs: ['anchor.schema.json'] },
+  { schema: 'collaboration.schema.json', refs: ['anchor.schema.json'] },
+  { schema: 'content.schema.json', refs: ['semantic.schema.json', 'academic.schema.json'] },
   { schema: 'phantoms.schema.json', refs: ['anchor.schema.json'] },
+  { schema: 'security.schema.json', refs: ['anchor.schema.json'] },
 ];
 
 let hasErrors = false;
diff --git a/spec/core/03a-anchors-and-references.md b/spec/core/03a-anchors-and-references.md
index 99e89a3..0b692c8 100644
--- a/spec/core/03a-anchors-and-references.md
+++ b/spec/core/03a-anchors-and-references.md
@@ -237,39 +237,65 @@ Implementations SHOULD validate that anchor targets (block IDs, named anchor IDs
 - `offset` MUST be non-negative
 - For valid ranges, `end` SHOULD NOT exceed the target block's text content length
 
-## 8. Shared Types
+## 8. Terminology Glossary
 
-### 8.1 Person Object
+This section defines anchor-related terminology used throughout the specification:
 
-The Person object is a base type used across multiple extensions to represent a person (author, signer, creator). Defining it once ensures consistency across the specification.
+| Term | Usage Context | Definition |
+|------|---------------|------------|
+| Content Anchor URI | Formal name | URI string referencing a content location (e.g., `#blockId/10-25`) |
+| ContentAnchor | Schema object type | JSON object representing an anchor with `blockId`, `offset`, `start`, `end` fields |
+| anchor | Shorthand | Informal reference to either Content Anchor URI or ContentAnchor object |
+| anchor mark | Mark type | A named anchor point within text (`{ "type": "anchor", "id": "..." }`) |
+| Content Anchor URI syntax | Pattern description | The `#id[/offset[-end]]` format |
+
+### 8.1 Content Terminology
+
+| Term | Description |
+|------|-------------|
+| `blocks` | Top-level array of block objects (used in root document and phantom content) |
+| `children` | Nested content within a block (paragraphs, list items, etc.) |
+| `content` | Plain text shorthand in specific contexts (e.g., footnote simple form) |
+
+The distinction is intentional: `blocks` represents a document-level content array, while `children` represents nested block content.
+
+## 9. Shared Types
+
+### 9.1 Person Object
+
+The Person object is a base type used across multiple extensions to represent a person (author, signer, creator). It is defined in `anchor.schema.json` for reuse across extensions.
 
 **Base Person fields:**
 
 | Field | Type | Required | Description |
 |-------|------|----------|-------------|
 | `name` | string | Yes | Display name |
-| `email` | string | No | Email address |
+| `email` | string | No | Email address (format: email) |
+| `identifier` | string | No | Persistent identifier (ORCID, DID, URL, institutional ID) |
 
 **Base example:**
 
 ```json
 {
   "name": "Jane Doe",
-  "email": "jane@example.com"
+  "email": "jane@example.com",
+  "identifier": "https://orcid.org/0000-0002-1825-0097"
 }
 ```
 
-Extensions extend the base Person type with additional fields as needed:
+For scholarly documents, the `identifier` field SHOULD use ORCID format (e.g., `https://orcid.org/0000-0002-1825-0097`).
+
+Extensions extend the base Person type with additional fields via schema composition (`allOf`):
 
-| Extension | Additional Fields | Description |
-|-----------|------------------|-------------|
-| Security (signer) | `organization`, `certificate`, `keyId` | Cryptographic identity |
-| Provenance (creator) | `identifier` | DID or URI-based identifier |
-| Collaboration (presence) | `userId`, `color` | Real-time collaboration identity |
+| Extension | Object Name | Additional Fields | Description |
+|-----------|-------------|------------------|-------------|
+| Collaboration | `author` | `userId`, `avatar`, `color` | Real-time collaboration identity |
+| Security | `signer` | `organization`, `certificate`, `keyId` | Cryptographic identity |
+| Phantoms | `author` | (none) | Basic author attribution |
 
-All Person objects MUST include at minimum the `name` field. Extensions SHOULD include the base fields alongside their extension-specific fields.
+All Person objects MUST include at minimum the `name` field. Extensions SHOULD include the base fields alongside their extension-specific fields. The naming distinction between "author" and "signer" is intentional to reflect the semantic difference in their contexts.
 
-## 9. Relationship to Extensions
+## 10. Relationship to Extensions
 
 The anchor system is defined in the core specification but is primarily consumed by extensions:
 
diff --git a/spec/extensions/README.md b/spec/extensions/README.md
new file mode 100644
index 0000000..d1716a3
--- /dev/null
+++ b/spec/extensions/README.md
@@ -0,0 +1,111 @@
+# Codex Extensions
+
+This directory contains specifications for Codex extensions. Each extension adds specialized functionality to the core Codex document format.
+
+## Available Extensions
+
+| Extension | ID | Version | Status | Purpose |
+|-----------|----|---------|----|---------|
+| [Semantic](semantic/README.md) | `codex.semantic` | 0.1 | Draft | Citations, footnotes, glossary, entity annotations |
+| [Academic](academic/README.md) | `codex.academic` | 0.1 | Draft | Theorems, proofs, exercises, algorithms, equations |
+| [Forms](forms/README.md) | `codex.forms` | 0.1 | Draft | Interactive form fields and validation |
+| [Collaboration](collaboration/README.md) | `codex.collaboration` | 0.2 | Draft | Comments, track changes, real-time collaboration |
+| [Security](security/README.md) | `codex.security` | 0.1 | Draft | Digital signatures, encryption, access control |
+| [Phantoms](phantoms/README.md) | `codex.phantoms` | 0.1 | Draft | Off-page annotation clusters |
+| [Presentation](presentation/README.md) | `codex.presentation` | 0.1 | Draft | Layout templates and rendering hints |
+
+## Extension Compatibility
+
+Extensions are designed to work together. The following matrix shows compatibility between extensions:
+
+| Extension | semantic | academic | forms | collaboration | security | phantoms | presentation |
+|-----------|----------|----------|-------|---------------|----------|----------|--------------|
+| semantic | - | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
+| academic | ✓ | - | △* | ✓ | ✓ | ✓ | ✓ |
+| forms | ✓ | △* | - | ✓ | ✓ | ✓ | ✓ |
+| collaboration | ✓ | ✓ | ✓ | - | ✓ | ✓ | ✓ |
+| security | ✓ | ✓ | ✓ | ✓ | - | ✓ | ✓ |
+| phantoms | ✓ | ✓ | ✓ | ✓ | ✓ | - | ✓ |
+| presentation | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | - |
+
+**Legend:**
+- ✓ = Fully compatible
+- △ = Technically compatible but unusual combination
+- ✗ = Incompatible
+
+*Academic and forms are both content-heavy extensions; combining them is technically possible but unusual in practice.
+
+## Common Patterns
+
+### Extension Declaration
+
+Extensions are declared in the manifest:
+
+```json
+{
+  "extensions": [
+    {
+      "id": "codex.semantic",
+      "version": "0.1",
+      "required": false
+    }
+  ]
+}
+```
+
+The `required` field indicates whether the document can be meaningfully viewed without the extension:
+- `false`: Document degrades gracefully without extension support
+- `true`: Extension is essential to document content
+
+### Extension Data Files
+
+Most extensions store data in dedicated directories:
+
+| Extension | Directory | Primary Files |
+|-----------|-----------|---------------|
+| semantic | `semantic/` | `bibliography.json`, `glossary.json` |
+| academic | `academic/` | `numbering.json` |
+| forms | `forms/` | `data.json` |
+| collaboration | `collaboration/` | `comments.json`, `changes.json` |
+| security | `security/` | `signatures.json`, `encryption.json` |
+| phantoms | `phantoms/` | `clusters.json` |
+
+### Shared Definitions
+
+Extensions share common definitions from the core specification:
+
+- **ContentAnchor** (`anchor.schema.json`): Position references used by collaboration, phantoms, annotations
+- **Person** (`anchor.schema.json`): Base identity object extended by collaboration (author), security (signer), phantoms (author)
+
+## Implementation Guidance
+
+When implementing Codex support, consider the following priority order:
+
+### Required for Basic Support
+1. Core content blocks
+2. Dublin Core metadata
+3. Manifest parsing
+
+### Recommended Extensions
+1. **Security** - For document integrity verification
+2. **Presentation** - For proper rendering
+
+### Content Extensions (as needed)
+- **Semantic** - For scholarly documents with citations
+- **Academic** - For mathematical/scientific content
+- **Forms** - For fillable documents
+
+### Collaboration Extensions
+- **Collaboration** - For multi-user editing
+- **Phantoms** - For advanced annotation workflows
+
+## Versioning
+
+- Each extension specifies its version in the manifest declaration
+- Data files include a `version` field matching the extension version
+- Version changes follow semantic versioning principles:
+  - Patch: Bug fixes, clarifications
+  - Minor: New optional features, backward-compatible
+  - Major: Breaking changes
+
+See individual extension READMEs for version history and migration notes.
diff --git a/spec/extensions/academic/README.md b/spec/extensions/academic/README.md
index 0ae3cdf..607f6b5 100644
--- a/spec/extensions/academic/README.md
+++ b/spec/extensions/academic/README.md
@@ -897,3 +897,49 @@ This produces: Theorem 1, Lemma 2, Proposition 3, Theorem 4, etc.
   }
 ]
 ```
+
+## 11. Author Identification
+
+For scholarly documents, author identification is critical for attribution and citation. The Codex specification uses a base `person` object defined in `anchor.schema.json` that includes an `identifier` field for persistent identifiers.
+
+### 11.1 ORCID Recommendation
+
+For academic documents, the `identifier` field SHOULD use ORCID (Open Researcher and Contributor ID) format:
+
+```json
+{
+  "name": "Jane Doe",
+  "email": "jane.doe@university.edu",
+  "identifier": "https://orcid.org/0000-0002-1825-0097"
+}
+```
+
+ORCID provides:
+- Unique, persistent identification across all scholarly outputs
+- Automatic disambiguation of authors with similar names
+- Links to affiliations, grants, and publications
+- Integration with major publishers and funding agencies
+
+### 11.2 Other Identifier Formats
+
+The `identifier` field also supports:
+
+| Format | Example | Use Case |
+|--------|---------|----------|
+| ORCID | `https://orcid.org/0000-0002-1825-0097` | Researchers (recommended) |
+| ISNI | `https://isni.org/isni/0000000121032683` | Name authority records |
+| DID | `did:web:example.com:jane` | Decentralized identity |
+| Institutional | `https://university.edu/faculty/jdoe` | University profiles |
+
+### 11.3 Dublin Core Integration
+
+Author identifiers should also be included in Dublin Core metadata (`metadata/dublin-core.json`) for discoverability:
+
+```json
+{
+  "creator": ["Jane Doe", "John Smith"],
+  "contributor": ["Research Assistant"]
+}
+```
+
+For richer author metadata, use the semantic extension's JSON-LD annotations to provide Schema.org `Person` objects with ORCID identifiers.
diff --git a/spec/extensions/forms/README.md b/spec/extensions/forms/README.md
index dc79cc5..1171285 100644
--- a/spec/extensions/forms/README.md
+++ b/spec/extensions/forms/README.md
@@ -192,6 +192,51 @@ For cross-field validation (e.g., password confirmation):
 }
 ```
 
+### 4.3 Conditional Validation
+
+Apply validation rules based on other field values using `conditionalValidation`:
+
+```json
+{
+  "type": "forms:textInput",
+  "name": "state",
+  "label": "State/Province",
+  "conditionalValidation": {
+    "when": { "field": "country", "equals": "us" },
+    "then": { "required": true }
+  }
+}
+```
+
+The `when` condition supports the following operators:
+
+| Operator | Description |
+|----------|-------------|
+| `equals` | Condition is true when the field equals the specified value |
+| `notEquals` | Condition is true when the field does not equal the specified value |
+| `isEmpty` | Condition is true when the field is empty (set to `true`) |
+| `isNotEmpty` | Condition is true when the field has a value (set to `true`) |
+
+Only one operator should be used per condition. When the condition evaluates to true, all validation rules in `then` are applied to the field.
+
+Example with multiple conditional rules:
+
+```json
+{
+  "type": "forms:textInput",
+  "name": "companyName",
+  "label": "Company Name",
+  "conditionalValidation": {
+    "when": { "field": "employmentType", "equals": "employed" },
+    "then": {
+      "required": true,
+      "minLength": 2,
+      "message": "Company name is required for employed individuals"
+    }
+  }
+}
+```
+
 ## 5. Form Data
 
 ### 5.1 Storage