You can have the flag left in when playing from off the green.
If you ask for the flag to be tended then the player tending the flag must remove it before the ball goes in the hole.
If you've asked for the flag to be tended and your ball hits the flag or goes in the hole with the flag still in then it's a penalty, 2 shots I think but don't quote me, so don't ask the player tending to leave it in if you've hit the ball too hard!
