Today I received a card from this girl who went to school with me, thanking me for the wedding present I'd sent her. The card was from her (who we'll call María Rodríguez) and her new husband (say, Juan Pérez?), and they signed:

Juan Pérez
María Rodríguez de Pérez

This is a custom that makes me really mad. "de" means "of", as in "belonging to". It used to be very common for married women here to sign like that, but lately I've been seeing that people my age have stopped doing it. Most of my married girlfriends have kept their own names, and their husbands have thought it the most natural thing in the world.