I just started hunting public land this year so I've been reading all the rules. I'm sure it varies in other states though. From what I read, you can hang stands on public ground. You cannot hang a stand before a certain date and you must remove your stand by another date. I believe you are supposed to have your name, address, and phone number readily visible on your stand. You cannot use a stand, steps, or anything else that pierce the bark. I'm still deciding on whether or not climbers are legal....I've talked with several wardens and it seems like there is no clear consensus on whether or not they are legal. As far as hunting someone else's stand, I don't believe there are any clearly written rules but I for one think it to be wrong and would consider it private property. In a sense, it does seem a bit like you are staking your claim to that area but I sure would be mad if I walk out to my stand to find somebody else in it....hence the name tag....maybe it is required on your stand for this reason as well.

EDIT: I understand how some are saying that a permanent (or lock-on) 'stakes claim' to that surrounding area and we should do away with this on public ground. I have some concerns with this. I'm still young and can effeciently use a climber. What about older hunters who can't use a climber? I'm sure there's plenty of hunters out there who can't use a climber because of age, joints, injuries, etc.etc. I don't have a problem with them....if they're in'your' spot(which is contradictory b/c public land should not be claimed) then simply hunt nearby, or if you think the other hunter might disrupt your hunt then hunt elsewhere.