$a is the Friendica 'App' class.
It contains a wealth of information about the current state of Friendica:
* which module has been called,
* configuration information,
* the page contents at the point the hook was invoked,
$a is the Friendica 'App' class.
It contains a wealth of information about the current state of Friendica:
* which module has been called,
* configuration information,
* the page contents at the point the hook was invoked,