At risk of repeating what has been said before, the courteous thing to do is ask before showing up in anything unusual. And, unfortunately, the kilt is still not one of the usual options of general wear for men in our culture. I may live to see it changed, I can remember when the absence of a necktie on any one other than a working man (not "white collar") would be cause for comment! Now look at what is worn out in public!