What was it used for, if not Physical Affair?
One acronym I use that others seem to not know is AFK for Away From Keyboard - used to explain why you might have not responded or not be able to respond for awhile.
I know we don't want to get too bloated with acronyms, but if you suddenly NEED to be AFK, it sure helps to be able say:
(away from keyboard, be back soon)
Uh-oh, one of my kids just clobbered the other one over the head with a Tonka truck and he's bleeding and convulsing, I gotta run him to the emergency room but first I gotta turn the stove off so the house doesn't burn down while we're gone, that's why I'm suddenly not talking to you! I'll come back to finish our conversation at some future time.