Update jakarta documentation

develop/index.md

@@ -84,6 +84,8 @@ for Greenfield implementation and
 
 for PDFBox implementation.
 
+If your project uses `core` or `verapdf-library` dependencies, they also have alternative jakarta versions (`core-jakarta` or `verapdf-library-jakarta` accordingly).
+
 ### GitHub for source code
 The up to date source repos are on GitHub.
 

policy/index.md

@@ -54,7 +54,7 @@ appropriate `features.xml` file, which should be used to overwrite your
 `<verapdf-install-path>/config/features.xml` file.
 
 ### <a name="fonts"></a> Fonts
-We'll work through tow examples, one to disallow a particular font the other ensuring that documents contain only a certain font.
+We'll work through two examples, one to disallow a particular font the other ensuring that documents contain only a certain font.
 
 In order to configure the feature extractor to generate font data please
 download this [features config file](font/features.xml) and replace the current

validation/index.md

@@ -3,7 +3,7 @@ layout: page
 title: veraPDF Validation
 ---
 
-The veraPDF validation engine implements the PDF/A and PDF/UA specifications using formalizations of each "shall" statement (i.e., each requirement) in PDF/A-1, PDF/A-2, PDF/A-3, PDF/A-4, PDF/UA-1 and  PDF/UA-2. These rules are implemented as XML documents known as Validation Profiles and are applied by veraPDF software at runtime.
+The veraPDF validation engine implements the PDF/A and PDF/UA specification using formalizations of each "shall" statement (i.e., each requirement) in PDF/A-1, PDF/A-2, PDF/A-3, PDF/A-4, PDF/UA-1 and PDF/UA-2. These rules are implemented as XML documents known as Validation Profiles and are applied by veraPDF software at runtime. In cases of PDF/UA only machine verifiable checks are performed. See [Matterhorn protocol](https://pdfa.org/resource/the-matterhorn-protocol/) for more details on definitions of Machine and Human checkpoints.
 
 [Read a little more about the veraPDF PDF/A validation model, rules and profiles.](./rules)