Two part question: What sort of dips and other precautions will everyone be taking before putting pieces (SPS and Zoas) from the swap in their tanks? Will any of these coral dips be available at the swap?
Like Chief said you can go to the Pest Id station.
As a precaution I think if someone knows they have a certain type of pest, they should let the buyer/trader know so they don't end up with the same pest. It's the right thing to do and you won't give someone else a world of headaches when their coral look unhappy.
Everyone, if they're getting SPS/zoas, should be ready to dip on their own if they are unsure of the source they are coming from.