Wife-beaters illegal in Iran?

You have to read between the lines to find what's interesting in a new story out of Iran. The BBC is reporting that two thousand people protested a new crackdown on "un-Islamic dress".

Two thousand young men in Iran have protested against new clothing curbs, reports say, amid growing discontent about a crackdown on un-Islamic dress.

Shiraz university students were angry about new rules banning sleeveless T-shirts, even inside all-male dorms.

Follow me on this. We call a "sleeveless T-shirt" a "wife-beater". Iran is a society that allows -- even promotes -- wife beating, but they ban the wife-beater shirt? That seems strange.