The issue is this: I'm using a PC keyboard with my (closed) MBP at work, and am using Karabiner (TAFKA KeyRemap4MacBook) to map the Mac keys to their appropriate places on it. So far so good.
However, on the number pad, adjacent to some volume buttons on the top row (which worked straight off, no mapping required) there's a key with a crescent moon on it, which would be perfect for inducing insta-sleep/lock. But I can't find it in Karabiner, or Keyboard Viewer in order to map said function to it! It doesn't show up anywhere, and pressing it gives no identifying feedback/input…
Any thoughts? Admittedly a very minor 'issue' but you know, one of those ones that, like an ear-worm, just won't leave me alone!
The keyboard in question is an Emprex 6310u (see the moon?):