I am not opening a new can of worms here, and I have read all posts, (I think), referring to sash's/plaids, but my question is;

What is the "protocol" for wearing a sash (not a plaid, fly plaid, pipers plaid, mini fly plaid, nothing "tartan") with a military style doublet. I have seen numerous pipe majors wearing a solid color sash across the chest, but colors vary. What do the colors represent, (rank?), and which shoulder does it hang from, and who should/should not wear it? This would be primarily for parade situations.