diff --git src/wp-admin/js/word-count.js src/wp-admin/js/word-count.js
index c0255fd..b32d227 100644
--- src/wp-admin/js/word-count.js
+++ src/wp-admin/js/word-count.js
@@ -1,10 +1,56 @@
+/**
+ * Word or character counting functionality. Count words or characters in a provided text string.
+ *
+ * @summary   Count words or characters in a text.
+ *
+ * @namespace wp.utils
+ * @since     2.6
+ */
+
 ( function() {
+	/**
+	 * Word counting utility
+	 * 
+	 * @namespace wp.utils.wordcounter
+	 * @memberof  wp.utils
+	 *
+	 * @class
+	 *
+	 * @param {Object} settings                                   Optional. Key-value object containing overrides for
+	 *                                                            settings.
+	 * @param {RegExp} settings.HTMLRegExp                        Optional. Regular expression to find HTML elements.
+	 * @param {RegExp} settings.HTMLcommentRegExp                 Optional. Regular expression to find HTML comments.
+	 * @param {RegExp} settings.spaceRegExp                       Optional. Regular expression to find irregular space
+	 *                                                            characters.
+	 * @param {RegExp} settings.HTMLEntityRegExp                  Optional. Regular expression to find HTML entities.
+	 * @param {RegExp} settings.connectorRegExp                   Optional. Regular expression to find connectors that
+	 *                                                            split words.
+	 * @param {RegExp} settings.removeRegExp                      Optional. Regular expression to find remove unwanted
+	 *                                                            characters to reduce false-positives.
+	 * @param {RegExp} settings.astralRegExp                      Optional. Regular expression to find unwanted
+	 *                                                            characters when searching for non-words.
+	 * @param {RegExp} settings.wordsRegExp                       Optional. Regular expression to find words by spaces.
+	 * @param {RegExp} settings.characters_excluding_spacesRegExp Optional. Regular expression to find characters which
+	 *                                                            are non-spaces.
+	 * @param {RegExp} settings.characters_including_spacesRegExp Optional. Regular expression to find characters
+	 *                                                            including spaces.
+	 * @param {RegExp} settings.shortcodesRegExp                  Optional. Regular expression to find shortcodes.
+	 * @param {Object} settings.l10n                              Optional. Localization object containing specific
+	 *                                                            configuration for the current localization.
+	 * @param {String} settings.l10n.type                         Optional. Method of finding words to count.
+	 * @param {Array}  settings.l10n.shortcodes                   Optional. Array of shortcodes that should be removed
+	 *                                                            from the text.
+	 *
+	 * @return void
+	 */
 	function WordCounter( settings ) {
 		var key,
 			shortcodes;
 
+		// Apply provided settings to object settings.
 		if ( settings ) {
 			for ( key in settings ) {
+				// Only apply valid settings.
 				if ( settings.hasOwnProperty( key ) ) {
 					this.settings[ key ] = settings[ key ];
 				}
@@ -13,16 +59,19 @@
 
 		shortcodes = this.settings.l10n.shortcodes;
 
+		// If there are any localization shortcodes, add this as type in the settings.
 		if ( shortcodes && shortcodes.length ) {
 			this.settings.shortcodesRegExp = new RegExp( '\\[\\/?(?:' + shortcodes.join( '|' ) + ')[^\\]]*?\\]', 'g' );
 		}
 	}
 
+	// Default settings.
 	WordCounter.prototype.settings = {
 		HTMLRegExp: /<\/?[a-z][^>]*?>/gi,
 		HTMLcommentRegExp: /<!--[\s\S]*?-->/g,
 		spaceRegExp: /&nbsp;|&#160;/gi,
 		HTMLEntityRegExp: /&\S+?;/g,
+		// \u2014 = em-dash
 		connectorRegExp: /--|\u2014/g,
 		removeRegExp: new RegExp( [
 			'[',
@@ -59,45 +108,84 @@
 				'\u2E00-\u2E7F',
 			']'
 		].join( '' ), 'g' ),
+		// Remove UTF-16 surrogate points, see https://en.wikipedia.org/wiki/UTF-16#U.2BD800_to_U.2BDFFF
 		astralRegExp: /[\uD800-\uDBFF][\uDC00-\uDFFF]/g,
 		wordsRegExp: /\S\s+/g,
 		characters_excluding_spacesRegExp: /\S/g,
+		/*
+		 * Match anything that is not a formatting character, excluding:
+		 * \f = form feed
+		 * \n = new line
+		 * \r = carriage return
+		 * \t = tab
+		 * \v = vertical tab
+		 * \u00AD = soft hyphen
+		 * \u2028 = line separator
+		 * \u2029 = paragraph separator
+		 */
 		characters_including_spacesRegExp: /[^\f\n\r\t\v\u00AD\u2028\u2029]/g,
 		l10n: window.wordCountL10n || {}
 	};
 
+	/**
+	 * Counts the number of words (or other specified type) in the specified text.
+	 *
+	 * @summary  Count the number of elements in a text.
+	 *
+	 * @since    2.6
+	 * @memberof wp.utils.wordcounter
+	 *
+	 * @param {String}  text Text to count elements in.
+	 * @param {String}  type Optional. Specify type to use.
+	 *
+	 * @return {Number} The number of items counted.
+	 */
 	WordCounter.prototype.count = function( text, type ) {
 		var count = 0;
 
+		// Use default type if none was provided.
 		type = type || this.settings.l10n.type;
 
+		// Sanitize type to one of three possibilities: 'words', 'characters_excluding_spaces' or 'characters_including_spaces'.
 		if ( type !== 'characters_excluding_spaces' && type !== 'characters_including_spaces' ) {
 			type = 'words';
 		}
 
+		// If we have any text at all.
 		if ( text ) {
 			text = text + '\n';
 
+			// Replace all HTML with a new-line.
 			text = text.replace( this.settings.HTMLRegExp, '\n' );
+			// Remove all HTML comments.
 			text = text.replace( this.settings.HTMLcommentRegExp, '' );
 
+			// If a shortcode regular expression has been provided use it to remove shortcodes.
 			if ( this.settings.shortcodesRegExp ) {
 				text = text.replace( this.settings.shortcodesRegExp, '\n' );
 			}
 
+			// Normalize non-breaking space to a normal space.
 			text = text.replace( this.settings.spaceRegExp, ' ' );
 
 			if ( type === 'words' ) {
+				// Remove HTML Entities.
 				text = text.replace( this.settings.HTMLEntityRegExp, '' );
+				// Convert connectors to spaces to count attached text as words.
 				text = text.replace( this.settings.connectorRegExp, ' ' );
+				// Remove unwanted characters.
 				text = text.replace( this.settings.removeRegExp, '' );
 			} else {
+				// Convert HTML Entities to "a".
 				text = text.replace( this.settings.HTMLEntityRegExp, 'a' );
+				// Remove surrogate points.
 				text = text.replace( this.settings.astralRegExp, 'a' );
 			}
 
+			// Match with the selected type regular expression to count the items.
 			text = text.match( this.settings[ type + 'RegExp' ] );
 
+			// If we have any matches, set the count to the number of items found.
 			if ( text ) {
 				count = text.length;
 			}