Oh, it's not an unwritten rule. Didn't you see the TOS change? Better be careful, or you'll drop below your T&A quota. ;)

I was on a business trip to France with an, shall we say, agressively American coworker. As we were walking around town, we kept seeing this add on street corner marques that was just a naked woman standing there, shown from slightly below waist up. Finally he got too curious, turned to our host, and asked "What is that an ad for? Obviously it's not clothes." :)