I've just found, that @since comment can be used to define a version since when functionality is available. For example:
/**
* [SCHEDULED TASK] Deletes expired sessions
*
* @param kEvent $event
* @since 5.1.0
*/
function OnDeleteExpiredSessions($event)
{
if (defined('IS_INSTALL') && IS_INSTALL) {
return ;
}
$this->Application->Session->DeleteExpired();
}
When next time developer will look at that method he can clearly see, that before In-Portal 5.1.0 this method wasn't available.
This would also help, when documentation is generated, because just looking at method comment we can understand if functionality is present in a given version.
To figure out when each of methods/classes is added we need to inspect SVN commit history.