ILIAS plugin development

Question

I'm working with a learning management system called ILIAS; trying to develop a plugin for the PersonalDesktopHook [pdhk] plugin slot.

Sadly I'm stuck with deploying the simplest plugin:

1. Created a directory for my plugin:

ilias/Customizing/global/plugins/Services/PersonalDesktop/PluginName

1. Created a plugin.php file as described in the documentation (with matching id, etc.).

2. Created a classes/class.ilPluginNamePlugin.php file containing a ilPluginNamePlugin extending the abstract ilPersonalDesktopHookPlugin class located in

ilias/Services/PersonalDesktop/classes/class.ilPersonalDesktopHookPlugin.php

Still my plugin isn't showing up in the Services/PersonalDesktop component menu (Administration).

Did I miss something or is the plugin development documentation out of date?

(I followed the ILIAS development guide's "Implementing Plugins" section.)