On the issue of Brand names

Are we to use the copyright: designation for brand name products? They certainly are trademarked and known well enough the world over to warrant it, because currently there doesn't appear to be any consistency at the moment with the way they are tagged eg. Dr_Pepper is, while coca-cola and fanta are not.

If the copyright has characters associated with it, then it gets the purple treatment, otherwise it stays blue. mcdonald's and kfc are purple because they have ronald_mcdonald and colonel_sanders, repectively, while the soft drinks aren't because they don't have anything attached to them other than label recognition.