Hanger - This an alternate term of a Call On signal on the PRR. The Call On condition would be represented by either a Restricting \ on the lower head or a single Stop and Proceed marker below the main head. In both cases the displayed signal appeared to hang below the --- on the upper head.
|The literal implementation|
Pot - PRR position light dwarf signal.
On the Light - A train is inside the approach block as shown on the tower model board. In PRR cab signal territory most interlockings had approach locking which required time to be run only when a train was actually approaching the interlocking.
Stick and Non-Stick Signals - These are alternate terms of controlled and semi-automatic signals. "Stick" signals were those which would drop and stay at Stop after a train movement and stay that way even if the lever was not reversed. Non-Stick, aka "semi-automatic" signals would have the signal act automatically as long as the lever was left reversed. I have encountered this term a few places, but it was standard in New Haven railroad operations.
Vertical - Slang term for a PRR position light Clear signal indication used by Long Island Rail Road crews,
Stacking - A feature of modern CTC dispatch systems that allow dispatchers to queue up routes at interlockings in an ad-hoc fashion.
Double Barreling - Running two parallel movements in the same direction on a double track main line.
Giving 241 - Reference to NORAC Rule 241 for giving permission past a stop signal.
Paperwork - Train orders, track authority and mandatory directives of all types that have to be copied down or received on paper.
Dark Territory - Anything that doesn't show up on the dispatchers screen, signaled or otherwise.
The Railroad - A point running from one controlled signal to the next. is "given" to the engineer when it is time to get to work.
That's all I can think of right now. I might occasionally return to this post to add more. Feel free to make your own suggestions in the comments.