Just about all subway station identification signs that were rendered in white enamel with black lettering have pretty much disappeared from the subways, as white lettering on black signage, introduced in the 1980s, has completely supplanted them. The one exception happens to be on signage meant for the eyes of train operator and motormen (and motorwomen) alone: signs mounted on or near platforms telling them where to stop the trains.
The Flushing Line, which celebrates its 100th anniversary between Queensboro Plaza and 103rd Street on April 21, 2017, is the only line running with trainsets of 11 cars instead of the usual 10 (or 8, on the C and M lines or 4 as in the G line). When the Flushing Line was using R-33 cars, they came as single units, not pairs, so that it was possible to add an extra car to Flushing Line trainsets. They are not the longest trainsets in the system; because IRT cars are 51 feet long and BMT/IND cars are 60 feet long, 51×11= 561 feet while 60×10= 600 feet.
This 11-car sign is at the west end of the 61st/Woodside platform…
…while this one is instantly recognizable as being at the west end of the Queensboro Plaza platform.
These are somewhat newer signs indicating that both 10 and 11 car trainsets can stop at this point.
I’ve never seen an 8-car trainset on the Flushing, but this sign mounted toward the east end of the 61st/Woodside station tells the operator where to stop.
“Comment…as you see fit.”