diff --git a/CHANGELOG.md b/CHANGELOG.md
index c7a097b..5f9aec3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,10 @@
 # CHANGELOG
 
+## 0.3.3
+
+- Feature: add `filter` option for series preset `RankSeriesRulePresetICPC`
+- Change: `contest.link` has been removed. Use `contest.refLinks` to declare all related external links
+
 ## 0.3.2
 
 - Feature: add `remarks` field
diff --git a/README.md b/README.md
index 6771053..49949b2 100644
--- a/README.md
+++ b/README.md
@@ -4,7 +4,7 @@ Standard Ranklist (srk) is a json format to describe many kinds of ranklists lik
 
 With srk, most of programming contest ranklists can be described in a standard format. It's easy to customize display style with different renderers and share everywhere.
 
-Version: `0.3.2`
+Version: `0.3.3`
 
 ## Files
 
diff --git a/demo.json b/demo.json
index 8bf592d..cff2c2d 100644
--- a/demo.json
+++ b/demo.json
@@ -1,6 +1,6 @@
 {
   "type": "general",
-  "version": "0.3.2",
+  "version": "0.3.3",
   "remarks": "This is a demo ranklist.",
   "contributors": [
     "bLue <mail@example.com> (https://example.com/)"
@@ -16,7 +16,12 @@
       1,
       "h"
     ],
-    "link": "https://icpc.baylor.edu/scoreboard/"
+    "refLinks": [
+      {
+        "title": "Original Ranklist",
+        "link": "https://icpc.baylor.edu/scoreboard/"
+      }
+    ]
   },
   "problems": [
     {
diff --git a/demo.ts b/demo.ts
index c06635d..4eeb0f7 100644
--- a/demo.ts
+++ b/demo.ts
@@ -2,17 +2,20 @@ import * as srk from '.';
 
 const ranklist: srk.Ranklist = {
   type: 'general',
-  version: '0.3.2',
+  version: '0.3.3',
   remarks: 'This is a demo ranklist.',
-  contributors: [
-    "bLue <mail@example.com> (https://example.com/)"
-  ],
+  contributors: ['bLue <mail@example.com> (https://example.com/)'],
   contest: {
     title: 'ACM ICPC World Finals 2018',
     startAt: '2018-04-19T17:00:00+08:00',
     duration: [5, 'h'],
     frozenDuration: [1, 'h'],
-    link: 'https://icpc.baylor.edu/scoreboard/',
+    refLinks: [
+      {
+        title: 'Original Ranklist',
+        link: 'https://icpc.baylor.edu/scoreboard/',
+      },
+    ],
   },
   problems: [
     {
@@ -65,7 +68,7 @@ const ranklist: srk.Ranklist = {
           },
         },
       },
-    }
+    },
   ],
   rows: [
     {
diff --git a/index.d.ts b/index.d.ts
index 47407d3..a2d0a2e 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -4,7 +4,7 @@ Copyright (c) algoUX. All rights reserved.
 ***************************************************************************** */
 
 export type Type = 'general';
-export type Version = '0.3.2';
+export type Version = '0.3.3';
 
 //#region common
 
@@ -29,6 +29,23 @@ export type TimeUnit = 'ms' | 's' | 'min' | 'h' | 'd';
  */
 export type TimeDuration = [number, TimeUnit];
 
+/**
+ * i18n string set.
+ * @example
+ * { "en-US": 'English', "zh-CN": '中文', fallback: 'English' }
+ */
+export type I18NStringSet = {
+  /** The fallback string if renderer cannot determine the language to use. */
+  fallback: string;
+  /** The key is the IETF BCP 47 language tag, and the value is the string for this language tag. */
+  [key: string]: string;
+};
+
+/**
+ * Text (i18n supported).
+ */
+export type Text = string | I18NStringSet;
+
 /** URL. */
 export type Link = string;
 
@@ -39,7 +56,7 @@ export type Link = string;
  */
 export interface LinkWithTitle {
   link: Link;
-  title: string;
+  title: Text;
 }
 
 /** Base64 string. */
@@ -100,23 +117,6 @@ export interface Style {
   backgroundColor?: ThemeColor;
 }
 
-/**
- * i18n string set.
- * @example
- * { "en-US": 'English', "zh-CN": '中文', fallback: 'English' }
- */
-export type I18NStringSet = {
-  /** The fallback string if renderer cannot determine the language to use. */
-  fallback: string;
-  /** The key is the IETF BCP 47 language tag, and the value is the string for this language tag. */
-  [key: string]: string;
-};
-
-/**
- * Text (i18n supported).
- */
-export type Text = string | I18NStringSet;
-
 /**
  * Contributor field. The email and url are optional.
  * @example
@@ -298,12 +298,6 @@ export interface Contest {
   /** Banner image. */
   banner?: Image | ImageWithLink;
 
-  /**
-   * The link to view original contest.
-   * @defaultValue Ignored by renderer.
-   */
-  link?: Link;
-
   /**
    * Reference links of contest.
    * @defaultValue Ignored by renderer.
@@ -436,6 +430,26 @@ export interface RankSeriesRulePresetICPC {
        */
       noTied?: boolean;
     };
+
+    /**
+     * Use filter to determine users to be included.
+     * Only if the user matches all filter options, it will be included as denominator.
+     */
+    filter?: {
+      byUserFields?: {
+        /**
+         * The field name of `user` to be filtered.
+         * @example 'organization'
+         */
+        field: keyof User;
+
+        /**
+         * The field match rule (RegExp constructor string) of `user` to be filtered.
+         * @example 'SDUT'
+         */
+        rule: string;
+      }[];
+    },
   };
 }
 
diff --git a/package.json b/package.json
index 517cfe9..642180d 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@algoux/standard-ranklist",
-  "version": "0.3.2",
+  "version": "0.3.3",
   "description": "Standard Ranklist",
   "types": "index.d.ts",
   "scripts": {