Over the years, destinations and routes were added to the roll signs.
Destinations such as "Astoria", "Ditmas Ave.", and "Forest Hills - Queens" did not exist when the standards were new.
Some curiosities I remember:
A route sign "GG Local" (never saw it used)
Route signs for the Nassau St. Loop trains which would appear where the "Via Bridge" or "Via Tunnel" usually went (larger roll signs only):
via bridge thru
NASSAU LOOP
then via tunnel to bklyn
(Or something like that. There was also the other varient with via tunnel first).
All three lines were on a single panel of the larger roll signs, the first and last lines were tiny and the "NASSAU LOOP" in the middle was about 1/2 size.
I do recall seeing Culver and West End Nassau Loop rush hour trains with these signs displayed in the late 1950s.