Index: wp-includes/comment-functions.php
===================================================================
--- wp-includes/comment-functions.php	(revision 33871)
+++ wp-includes/comment-functions.php	(working copy)
@@ -1631,13 +1631,27 @@
 
 	if ( 'spam' !== $commentdata['comment_approved'] ) { // If it's spam save it silently for later crunching
 		if ( '0' == $commentdata['comment_approved'] ) {
-			wp_notify_moderator( $comment_ID );
+	  /**
+	 	 * Notifies the Moderator when a Comment Needs Approval.
+	   *
+	   * @since 
+	   *
+	   * @param int $comment_ID       The comment ID.
+	   */
+				do_action( 'wp_notify_moderator', $comment_ID );
 		}
 
 		// wp_notify_postauthor() checks if notifying the author of their own comment.
 		// By default, it won't, but filters can override this.
 		if ( get_option( 'comments_notify' ) && $commentdata['comment_approved'] ) {
-			wp_notify_postauthor( $comment_ID );
+    /**
+     * Notifies the Post Author of a New Comment.
+     *
+     * @since 
+     *
+     * @param int $comment_ID       The comment ID. 
+     */
+				do_action( 'wp_notify_postauthor', $comment_ID );
 		}
 	}
 
Index: wp-includes/default-filters.php
===================================================================
--- wp-includes/default-filters.php	(revision 33871)
+++ wp-includes/default-filters.php	(working copy)
@@ -334,6 +334,12 @@
 add_action( 'split_shared_term', '_wp_check_split_nav_menu_terms', 10, 4 );
 add_action( 'wp_split_shared_term_batch', '_wp_batch_split_terms' );
 
+// Default Notification Filters.
+add_action( 'wp_notify_postauthor', 'wp_notify_postauthor' );
+add_action( 'wp_notify_moderator', 'wp_notify_moderator' );
+add_action( 'wp_new_user_notification', 'wp_new_user_notification', 10, 2 );
+add_action( 'wp_password_change_notification', 'wp_password_change_notification' );
+
 /**
  * Filters formerly mixed into wp-includes
  */
Index: wp-includes/user-functions.php
===================================================================
--- wp-includes/user-functions.php	(revision 33871)
+++ wp-includes/user-functions.php	(working copy)
@@ -1915,8 +1915,14 @@
 
 	wp_set_password( $new_pass, $user->ID );
 	update_user_option( $user->ID, 'default_password_nag', false, true );
-
-	wp_password_change_notification( $user );
+	/**
+	 * Notifies of a Password Change.
+	 *
+	 * @since 
+	 *
+	 * @param object $user       The user. 
+	 */
+	do_action( 'wp_password_change_notification', $user );
 }
 
 /**
@@ -2003,9 +2009,16 @@
 	}
 
 	update_user_option( $user_id, 'default_password_nag', true, true ); //Set up the Password change nag.
+	/**
+	 * Notifies of a New User.
+	 *
+	 * @since 
+	 *
+	 * @param int $user_ID       The user ID. 
+	 * @param string $notify  (Optional) Whether admin and user should be notified ('both') or only the admin ('admin' or empty).
+	*/
+	do_action( 'wp_new_user_notification', $user_id, 'both' );
 
-	wp_new_user_notification( $user_id, 'both' );
-
 	return $user_id;
 }