I think the only way to enforce would be a) for mods to be able to see who nominates and b) nominating but not signing up puts you on the NYR list for *next* yuletide and/or disqualifies you for getting pinch hits this year. And they would also have to put in serious effort to hunt down socks, of course.

I think well before they did that though they would either reduce max noms per person/increase min offers per person, or they would completely change the way noms are done.

People like you, coalie, who just want to see the world burn, would figure out a way get in no matter what, but if we cleared out most of the people who are just nomming as a favor for a friend or who are nomming on spec but don't really think they'll sign up this year or are nomming because they want to treat but not sign up, it would probably reduce the level to where it wasn't causing problems. And honestly a polite request or two would likely work for that.