Several New York City Subway service labels have never been used, but have appeared on rollsigns. DD, FF and MM are covered in the D, F and M articles. The others are included here.
IRT numbers
An R62A car in Corona Yard showing a 12 sign.
Current rollsigns include the following:
- Green 8, 10 and 12 (the same color as the 4, 5 and 6)
- Purple 11 (the same color as the 7 and its diamond service)
- Red 13 (the same color as the 1, 2 and 3)
- Red 9, unused since May 27, 2005
It is likely that these were assigned arbitrarily, for use if a new service is inaugurated over existing trackage.
IND/BMT letters
- P, T, U, X and Y appear on some current rollsigns as a black letter on a white circle. No current services use this color, so the signs would likely be patched if any of these services were to become permanent. T is the planned label for the new Second Avenue Line, and would be colored turquoise.
- In the 1990s, P (short for Penn Station) was planned for a nonstop between Sutphin Boulevard–JFK (at the LIRR's Jamaica station) and 34th Street–Penn Station, continuing locally to 168th Street, via the BMT Archer Avenue Line, BMT Jamaica Line, Chrystie Street Connection, IND Sixth Avenue Line and IND Eighth Avenue Line (switching to the latter at West Fourth Street). This would have been used during a threatened Amtrak strike that would have prevented LIRR trains from entering Penn Station.
- I and O have never been used due to their similarity to the numerals 1 and 0 respectively.
- P was skipped in the 1960 assignment of letters to BMT services.
- T was used for BMT West End Line services, but was quickly replaced by the expanded B service after the post-Chrystie Street reorganization.
- Y has at times been proposed for the Second Avenue Line, although the current plan is to name it T.
- The JFK Express bullet, featuring an airplane inside a blue circle, was used from 1978–1990, and is still present on rollsigns on various IND line trains today.
