Quote Originally Posted by Caradoc
To the best of my knowledge, they don't "signify" anything at all.

They're representative of the ribbons/garters used to hold up the hose in an earlier time - my own garters for "historical costume" are strips of tartan left over from making the moggans (footless stockings, made from tartan cut on the bias).

Today, the garters are elastic, and the flashes are purely decorative.
Yes, Caradoc is correct.