Only the arms of certain families are restricted by law. Such families may or may not also be clan chiefs in law. Tartans are not regulated in who may wear them in law, including Balmoral. The latter restriction is one of convention rather than law. There was an article in The Times of London the other week on this very subject. A link is attached to the syndicated story from The Australian newspaper.

http://www.theaustralian.com.au/news...5b93ab4dd1d649