Do all pipers wear kilts?

[OC Richard]

WUSPBA rules state

"Therefore, appropriate conduct at Highland games sanctioned by the WUSPBA includes promptness at all events; the wearing of appropriate Highland dress while on the field; ..."

RSPBA rules state

"Dress
3.47 At all contests Bands must appear in uniform dress which must be the same except for minor detail, e.g. where Drummers wear uniform different to that of the Pipers.

3.48 Any further exception must have the approval of the National Council."

As mentioned above, evidently EUSPBA does not have rules about dress but I've heard it stated that "most" individual contests require Highland Dress both to compete and to receive prizes. I wonder which contests do not (if any), and what pipers wear at these contests.