I suppose the definition of what is a "proper" kilt could be expanded to include the PV kilts, as Matt already mentioned, and five yard kilts, which I think are eminently practical for a lot of situations. I expect that in Scotland where, by all reports, one is likely to catch some flak for just wearing a kilt, one would get even more of a hard time if he was to show up in anything less than eight yards of worsted in their own clan tartan.

Best

AA