Manufacturer mark on upper question

I’ll be the first to admit, I know very little about the manufacturer marks on the uppers on AR15s. I know there are a lot of folks that are the same way. Maybe there should be a sticky somewhere on this board that that a person can reference.

                                          -The question-

I just got a new AR15 that has what looks like a keyhole mark on the upper. Anybody know who the manufacturer is? My wife took the camera and won’t be back for about two weeks, so I can’t post a picture.

http://m4carbine.net/showthread.php?t=5357&highlight=keyhole

Thanks for the help.