In some cases, it stands for Union of battle time experts. They were so far the greatest and most elite players that came into age of empires and warcraft II and dominated their competition. Some members migrated to counter-strike, and even to gears of war.
Even though some people may say it stands for university of berlington texas, uttermost official beginning that explained xtasy, and other sad clans out there that try to steal the name, these aren't the real people.
In other words, uobtex means being an elite player.
I just saw an uobtex playing gears of war, and he's really good!
Wow, these kids are named uobtex but aren't good.
If i'm good enough, im going to try out for uobtex.