It gets confusing doesn't it? Outside of physics and its children, few if any of the other sciences are still calling something a "law". Most of biology, for instance either uses theory or occasionally "rule". Maybe because physicists can't stand ambiguity ("law" sounds so much more permanent, doesn't it?), whereas biologists thrive on it (after all, rules are meant to be broken
). I dunno, that's sort of just my opinion.
Bottom line: there really isn't any hierarchy of confidence reflected in the terms used. In biology, "law" is pretty archaic and no longer used. IIRC, almost all of the original biological "laws" have been shown to be wrong in whole or in part. Biology simply doesn't appear to lend itself to "unbreakable laws" - there are just too many exceptions in nature.
My two cents.