Overrides in the event table lists

I have been doing some changes as an override in the /common/events_table.php changing what fields are visible and adding some more information for the registration status. We have several recurring events that make the list of events very long. The participants need to register only for the parent event, not for the child events of hese recurring events. The parent events have individual registration enabled and the child events have registration disabled.

Now, I wonder what code I need to identify the child events in that file so that I can make the child events not show up in the list. I still want to show standard events that have registration disabled, so "if ($item->registration_type != 3)" is not enough - that renders all those events invisible... I need something more, but can't figure it out... :side:

if ($item->parent_id > 0)
{
//This is child event
}

That code above should help

Tuan