I'm not 100% clear on the rules for each server. However, I'm fairly certain that creating a teleport underneath the map is not allowed. I have discovered Road runner doing just that. He has been putting it underneath the enemy base and spamming from there. I was on BR server when I found him doing so. He was on my team, but either way, it's just like every other cheat to me...not right!

I'm pretty sure that's not allowed. I can't say about BR but I don't allow it in my clans server.
I'm sure most people would agree that that's pretty damn unfair.

actually getting under the map is an easy feat and i think its silly that its not allowed in some servers i know thats not what plas had in mind when he made ghost pack for necro plas has even made maps with passages under the map like roach motel for example and i have seen many other maps where the underground is used its not hard to get under the map and there is no map where it is extremely deadly when a player is under the map being that the only weapons a player can use is nuke type guns and os its not like they can snipe you just imo though