When I find myself talking to random MMA fans that seem to be pretty big fans I often wonder if they are UGers, but I would never ask. Lets compile a list of subtle ways to tell if someone is one of us.
Wear a shirt that says "I wild each it" . Should be easy from there.
It's the guy wearing a tapout shirt with a Mohawk and bandana, and walking around with his giant cock hanging out while screaming "WHERE YOU AT GEORGES??!?"
Easiest way to spot a UGer. 
check if he has a micropenis. if so, hes a uger
lol.. great so far.
Make a rational, intelligent argument that (insert fighter's name) is over-rated, chin is going out, over the hill, record is padded, etc.
Might have to try a few fighter names to get a reaction.
But if he comes back at you with an irrational, nut-hugging attitude while his index finger starts twitching in a futile attempt to vote you down: You spotted a UGer
Mention Dana White, then watch them froth at the mouth.
Call them an egg and see how they react
When trying to have a conversation and they keep interrupting me saying "vote the fuck down" I know it's a UG'er.
Check his ankle for a tracking monitor.
graciesrule - Carlos & Helio's original 9 th degrees need to be in it: Carlson, Robson, Pedro Hemeterio, Armando Wreidt, Helio Vigio, Joao Alberto Barreto.Robson and Joao Alberto will def both be in the movie. There will be stories about the others but our focus is on the remaining, accessible masters.
GM Robson said this morning he will also use the resources of the FJJ Rio to help us with this project.
The hand sign?
trane and master the sidestep
If he goes from six to midnight when a Diaz brother is mentioned, he's probably a UGer. 
Kick things off by saying "Hey fuckface, you're looking thick, solid tight, kinda like that Fedor a million ankles although I still think rickson by armbar unless he side steps."
If you're watching the ufc at a bar and hear a dude shouting to sidestep- he's an uger.
Look in basement windows?
If u hear them blame trt for everything