I have two fairly basic questions about cap badges:

First, I remember reading somewhere that it was gauche to wear your clan crest badge when you're wearing your clan tartan. Is this true?

Second, since the amalgamation of the highland regiments, what is the status of their traditional cap badges? I don't want to spend money on a badge that I shouldn't be wearing as a civilian, though I think the badge of the Gordon Highlanders is very sharp and if I wouldn't be committing a faux pas I'd like to get one.

Thank you for any and all advice, here.