Tri / Triathlon / Triathlons - do they float your boat?

Just mulling some things over before Challenge Henley this weekend, and I dimly recollect that there was some kurfuffle a couple of years ago about whether or not compression calf guards were allowed to be worn underneath a wetsuit during the swim. Having had a couple of years away from racing tris, I have no idea if this was resolved or not. Are compression calf-guards allowed?
I doubt that any marshals will be checking you during transition - it's only champs races where the marshals look out for this sort of thing.

IIRC, BTF rules state that a swimsuit is 3 pieces max.