GUID ban?

Hey guys i was swim hacking with my test account with a hw spoofer on urban ops when i guy start threatening me about hw banning me. I tell him i spoof. Then he says ip ban and i say i can just change my ip. Then he mentions GUID ban which he really never explained to me what it was. Could someone explain to me what a GUID ban is and what it stands for? Thanks

sorrt but i dont no waht it is try searching google or yahoo www.google.com www.yahoo.com tell me if it helped