1. Post with your character.
2. That character is compelled to follow the orders of anyone who replies.
3. Any orders.
4. Any orders.
There's nothing in the rules about whether or not your character knows s/he must obey - as well, the other character might not know that s/he must be obeyed. Play it however you like.
Don't like the orders you got? Not willing to have your character follow them, even if you've had a good time up to this point? Talk to the other player, use OOC notes or PMs, try and work it out.
Got some stuff you'd never want to play out? Consider making a preferences post and linking to it when you reply here.
Wanna give orders that people would love to follow? Give 'em context. Make it a story. Is this about revenge? Working out some personal issues? Too dumb to realize that the other guy has to do whatever your guy says?