"National Garments" ... yeah, I guess they do what they can to hype it up and make it fun, but they are costume parties, try dressing like that at any other convention ... in the UK do the sisters wear Victorian gowns with plunging necklines and the brothers top hats or powdered wigs, perhaps a coat of armour?
It would be interesting to see brothers and sisters from New Guinea arriving, men wearing their traditional penis sheath and women in grass skirts and topless.