Usually reads "Exile target permanent", but it can also serve as bounce, or return something to the stack if e.g. your opponent gained control of it. With libraries, I think it probably puts them on top of the library.

­:)

What happens if you choose "stack"?

I'll gladly put your Primeval Titan in the ante zone.

CH: Hmm... probably as worded at the moment, you get control of the spell it becomes. Wording should probably say "Its owner puts it in that zone", which is fairer.

SM: Hahaha... good point, I forgot about that one...

Ooh, I choose my library for your Jace, the Mind Sculptor

I guess putting it in the command zone wouldn't be much different than exiling it...

Chris: Unfortunately if you try to put an opponent's card into your library, it goes to their library instead.

Which brings up a question: If you do choose library, where in that zone does it go? Top, bottom, a shuffle pulled out of thin air, or laid on its edge against the other cards to be drawn when its owner chooses?

Also, moving to stack doesn't quite work for land cards (the rules don't know what to do), or Aura cards (the one type of permanent spell that has a target, but since you never go through the act of casting when you just plunk something onto the stack, the target can't be properly initialize()d).

Where in the library: I said in the first comment that I guess it'll go on top of the library. The rules don't really handle effects that don't specify where, though, you're right. I suppose the card could say "Put target permanent on top of that zone"?

Auras: Hm. I could see ruling that you choose a target for the Aura spell at the moment that you put it onto the stack, or equally that it just has to choose somewhere to go after resolution, like if it were appearing thanks to Replenish or Show and Tell.

Lands I'll admit are a problem.

Would be cute if you put a card into the phasing zone, as a way of protecting it. It would come back during your next untap step with haste...

Too bad phased out is no longer a zone, instead becoming a status like tapped or flipped.

Terrible, and true, unfortunately. Why did they bother removing the zone? It seems more confusing to have cards in play that can't be effected by the game...

The current approach works more closely to the original intent of phasing. This way timestamps and counters and so on don't need special rules to bring them back - they just stick around almost automatically.