Trade Specialty Thread Status

Hi! I tried to look for this but didn't see it, sorry if I missed the info somewhere!

Does a thread have to be closed to count toward a specialty or can it be in progress?

And if so does it have to be a complete "plot" -- or if you only got a couple replies in before the other player went inactive, will that count?

Or is this generally up to the individual PM reviewing it?

Thanks!