This is a personal meme created by QuinKilo, not on NR, but on NF's Random RPG. It had gotten so random that Quin, playing as himself, often found himself outside the normal conflicts and, not wanting to join in, passed the time by raising his eyebrow.
It is estimated that he made about fourty-plus posts including the action.
It didn't reach meme status until he came over to NR via Sylux's sig, where Quin used it once in awhile in increasing frequency. About a few days later, for about two hours his sig composed of the three words in giant orange font, then toned it down and added the prerequesits in which he will raise it:
"If one of the posts above this one is deemed odd, crazy, random, etc by Quin, the following will be done:*Quin Raises Eyebrow*"
"The Quin Ultamatums, as told by Masky:
After Quin found that out, he raised his eyebrow.
If Quin stops raising his eyebrow, then it's a sign of the apocalypse."
Many members have drawn from these, mostly the second, and have jokingly deduced that several problems were caused by Quin not raising his eyebrow.
Chopstix, however, thinks its the most annoying thing on the forum.
It remains in his sig though, and it's not going anytime soon.