Added docstrings, updated messages.

shared/_locales/en/messages.json

 {
     "extensionDescription": {
-	"message": "Correct the display and quoting of links mangled by Microsoft Defender for Office 365 Safe Links.",
+	"message": "Correct the display and quoting of links mangled by Microsoft Defender for Office 365 Safe Links or Barracuda Link Protection.",
 	"description": "Description of the extension."
     },
 

shared/_locales/sv/messages.json

 {
     "extensionDescription": {
-	"message": "Korrigera visning och citering av länkar manglade av Microsoft Defender för Office 365 Safe Links.",
+	"message": "Korrigera visning och citering av länkar manglade av Microsoft Defender för Office 365 Safe Links eller Barracuda Link Protection.",
 	"description": "Description of the extension."
     },
 

shared/patterns.js

@@ -25,23 +25,52 @@
 
 const safelinksPatterns = [
     {
+	name: 'Microsoft Defender For Office 365 Safe Links',
 	host: '*.safelinks.protection.outlook.com',
 	path: '[?]url=([^&]+).*'
     },
     {
+	name: 'Barracuda Link Protection',
 	host: 'linkprotect.cudasvc.com',
 	path: 'url[?]a=([^&]+).*'
+    },
+    {
+	name: 'Proofpoint (v3)',
+	host: 'urldefense.com',
+	path: 'v3/_+([^_]+).*'
     }
+    // {
+    //	 name: 'Proofpoint (v2)',
+    //	 host: 'urldefense.proofpoint.com',
+    //	 path: 'v2/url[?]u=([^&]+).*',
+    //	 proc: (string) => string.replace('_', '/')
+    // }
 ];
 
+
+/**
+ * Compute a list of url patterns from the link patterns.
+ * @returns {Array} - Array of patterns.
+ */
 function computeSafelinksMatchPatterns() {
     return safelinksPatterns.map(({host, path}) => '*://' + host + '/*');
 }
 
+
+/**
+ * Escape a hostname pattern for use in a regexp.
+ * @param {string} host - The host name pattern.
+ * @returns {string} A suitable regexp.
+ */
 function escapeHostname(host) {
     return host.replace('.', '[.]').replace('*', '[^/]*')
 }
 
+
+/**
+ * Compute a regexp that matches all mangled links.
+ * @returns {RegExp} A regexp that matches all possible mangled links.
+ */
 function computeSafelinksRegexp() {
     return new RegExp('(?:' +
 		      safelinksPatterns.map(
@@ -51,4 +80,5 @@ function computeSafelinksRegexp() {
 	'gi');
 }
 
+
 const safelinksRegexp = computeSafelinksRegexp()