Where to wear the Glengarry??

[gilmore]

Actually, it just occurred to me that there is at least one other rule; don't wear feathers in your bonnet. One connotes an armiger (a gentleman with a Royal grant of arms), two a chieftain, and three a clan chief. This is not mere social convention, but dictates from the Lord Lyon of Scotland.

Take a look at the pics in the links in my post above of Tartan Army guys. Many have more in their glengarries that Lyon would allow for the sovereign. Wearing feathers is very much a social convention it seems.