6.2.1.1 Plugin Name

The name of the plugin as it appears in the pse.plugins package is determined by the global module variable plugin_name, which must be a string.
Note: In versions prior to PSE 3.0, the plugin name was derived from the file name of the plugin itself. While your PSE 2.x plugins will still function in PSE 3.0, you need to update your plugin to define plugin_name to be compatible with future versions of PSE.

New in version 3.0.