Film Signs:

So, if you're in LA, it's not long before you'll see a yellow sign with some cryptic-looking words or letters and an arrow, or occasionally less cryptic ones that say things like "Trucks" or "Base Camp." These are signs for film sets, and here's some codes I've seen around:

APT 23 - "Don't Trust the Bitch in Apartment 23" (Pilot)
B & B - ??
CASTLE - Castle. They aren't very subtle.
CM - Criminal Minds
CM SSP - Criminal Minds: Suspect Behavior
CSI:NY* - They go one further than Castle and slap their logo on it.
J EDGAR*- "J. Edgar" (movie w/ Leonardo DiCaprio)
LOLA* Law & Order: LA
N-LA - NCIS: LA
NT - ??
RABBIT - ??
TRUE* - True Blood
TW* (Red on white) - Torchwood: Miracle Day
VOICE* - The Voice




A few more that I've heard of:
BAD WOLF - Rumor has it, this was the former name on the signs for Torchwood. However, since I can't imagine a better way to get every Whovian in a 10-mile radius to investigate something than slapping up signs that say "Bad Wolf" with an arrow on them all over the place, it's understandable why they may have changed this.
ARTEMIS - The Hunger Games, in a much better naming decision.
GROUP HUG - The Avengers movie.

*Confirmed through various interesting incidents.