How to use @package & @subpackage in phpdoc?

I'm wondering how I should use @package & @subpackage for class doc.

let say I've the following class

class My_Controller_Action_Helper_MyHelperAction extends Foo_Bar {}

Should it be:

@category    My
@package     Controller
@subpackage  Action_Helper

or

@category    My
@package     Controller
@subpackage  Action_Helper_MyHelperAction

or

@category    My
@package     Controller_Action
@subpackage  MyHelperAction

or

@category   My
@package    My_Controller_Action
@subpackage MyHelperAction

What if use namespace instead of '_'?