How common is the wear of a Plaid that is a different tartan than the Klt?

[figheadair]

Do not mix plaids. I don't event mix tartans within the same clan, like MacKenzie modern and MacKenzie hunting. Just don't do it. It looks bad. If the military does it, it is for a specific reason.

Really? I don't see what the problem is, nor do others such as Clanranald (already posted by Nathan) or Donanld Cameron of Lochiel

Two different tartans may be worn together quite properly as long as they are tartans of the same clan (hunting, dress, ancient, modern, weathered etc.) but never tartans of different clans.

This of course implies that tartan associations are set hard and fast, which they are not. I might choose to wear a MacDonald related kilt and a plaid in what is now called MacIntyre but in reality is an old 18th century sett that pre-dates its adoption by the clan. Is that wrong? Or how about wearing a Munro plaid, again, a tartan that is much older than its current clan connection. There are many more examples, all of which go to show that trying to apply 'rules' to tartan is like running on quicksand - likely to sink at the first step.