As calls to the menu creation functions are made by the core WordPress code and all active plugins, the system builds an array containing all the items that will be displayed to the current user based on their access level. This recipe's code accesses the WordPress global variable containing this array and simply inserts an extra element under the ch3mlm-main-menu parent menu that was created in the previous recipe. The data that gets added is an array containing three elements: the label of the menu item, the permissions required to see the item, and the URL that will be assigned to the new menu link.

While this code works in current versions of WordPress, and has worked for many versions, there is a chance that it might no longer work at some point if WordPress changes the way it builds its menus. That being said, if changes are made to the way that menus are constructed, there will likely be new APIs introduced to reproduce this functionality, as it is widely used.