I report every post that is breaking the rules, then explain to the user what rule is broken to prevent them from breaking it further, as a lot of people who join don't even read them.
I see no harm in that, and putting a rule in place is pointless, just because it "annoys," some user. Really it does more help than harm. It cuts some of the work for the staff, and encourages members to inform people of the rules and be good role models.