PM means Private Message, like sending an e-mail thru GBO.
When a new post is made, the post goes to the top of that forum.
As other posts are made, it drifts down the list.
When someone repsonds to your post, it "bumps" to the top of the list again.
The trading rules talk about "bumping it to the top" yourself to get exposure, or BTT.
read those rules, before you do it. read all of them.
When a trade or sale is agreed to made, they "lock" the thread so folks won't post to it anymore. So the person who originates the ad asks the moderator to lock the thread: Please lock, or Lock it up. With no new posts, it eventually drifts down to the bottom and out of sight.
