How does one join team games?

I think I understand how the matchmaker function works, but I gather that team games often originate through the rooms under the custom game tab. I don't anticipate wanting to participate in mass games with dozens of players - those seem a bit too chaotic for me. But is it possible to join small-to-mid size team games? Are they designated as such in certain rooms or how?
thanks,
Stanley

Yeah, thanks, I guess basically it is. I didn't realize that was broken out like that.
Does anyone use those?

You can create a custom open lobby and use the command

quote: !maxplayers [number]

to set a max of 4v4(use 8 for 8 players), and you might get players looking for small teams. There is the one lobby with the reputation of leaning towards 16v16, but like the phases of the moon you'll see a small teams lobby pop up every now and then. Sometimes it's the dedicated [A] Small Teams room, but this starts from 0 players or a couple hop over there from the lob pot. Frequently, the small teams room is dominated by 90th percentile players when it exists so that can also look daunting.