I believe the distinction being made in [this answer](http://meta.moderators.stackexchange.com/a/150/83) is too nuanced for this site; that's not how everybody actually uses those words and maintaining two tags with that distinction is not going to work out well.  We should definitely not have two tags.

However, combining them into a single [tag:rules-and-policies] tag would be acceptable; anybody who starts typing either "rules" or "policies" will get there (no synonyms needed).