Trace filters: How the hell do they work?

What are valid filters for util.QuickTrace? I’d like to get a line, from point A to B, illustrated by an effect (which I have), but how do the trace filter work? Do they indicate where the trace stops? Or do they indicate what the trace ignores?

It is a table or just an entity of what the trace ignores.

Thanks.

Sorry for the bump, but what are the filters for tracers? I know that ply.Entity is a must, otherwise the player’s trace returns itself, but what about world filters?

Unless you want the trace to ignore anything, the player is the only one you need. (you don’t need .Entity)
Incidentally, it’s ‘traces’, ‘tracers’ are a certain type of bullet.

Right, but I want the trace to ignore the world as well. Ah well. I’ll just experiment around with it.