See New York City Subway nomenclature for a complete explanation; this is just a table of when each service has existed (and been signed for the public). Shuttles were SS until 1985, when they became (which had been used for specials). See here for the colors used for shuttles in 1967; in 1968 all six became green, and in 1979 all shuttles became dark gray. See also List of New York City Subway lines New York City Subway nomenclature Unused New York City Subway service labels Staten Island Railway References Subway services