What is it?
Some of the older guys will know. Some won't. Reason being, they keep changing alllllllll the terms I learned when I was there.
Googling is Verboten. In American that means it's a no no. Besides, I googled a couple pages. Some of us didn't have the simple luxury of the internet and search engines back then. We learned through our training, talking to those that have been there or the old standby..... the library. This is simple to explain. Well, it was in my day. We also followed it everytime we went out at night. Hmmm. Nice clue.