Hey @Afrodude, I took another look at this:
As you know Group mentions are only allowed for certain groups which can be configured in the settings of ACP. So when someone posts a group mention I check if the user is in the allowed groups, however when that person posts as "Anonymous" IPB returns a Guest account for the author, here is the code piece below:
if( $this->isAnonymous() )
{
$guest = new \IPS\Member;
$guest->name = \IPS\Member::loggedIn()->language()->addToStack( "post_anonymously_placename" );
return $guest;
}
So I can't check if that user is in the allowed groups, so the only way to make this work would be to allow everyone who posts as Anonymous to use group mentions but that doesn't sound like a good idea to me 😛