Clarify that 'html' refers to the Text editor tab, see #20993

git-svn-id: http://core.svn.wordpress.org/trunk@21218 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/class-wp-editor.php

@@ -76,6 +76,7 @@ final class _WP_Editors {
 		if ( self::$this_quicktags && self::$this_tinymce ) {
 			$switch_class = 'html-active';
 
+			// 'html' and 'switch-html' are used for the "Text" editor tab.
 			if ( 'html' == wp_default_editor() ) {
 				add_filter('the_editor_content', 'wp_htmledit_pre');
 			} else {

wp-includes/general-template.php

@@ -1767,7 +1767,7 @@ function user_can_richedit() {
  * Find out which editor should be displayed by default.
  *
  * Works out which of the two editors to display as the current editor for a
- * user.
+ * user. The 'html' setting is for the "Text" editor tab.
  *
  * @since 2.5.0
  *