S2 or S II may refer to: Science and technology S2 (star), Milky Way galaxy S/2007 S 2, a natural satellite of Saturn Disulfur (S2), an allotrope of sulfur S2: Keep out of the reach of children, a safety phrase in chemistry S2 steel (shock resisting steel) S2 map projection, a map projection created at Google Mathematics S2, the two-dimensional sphere S2, the permutation group on two elements Biology and medicine British NVC community S2, a swamps and tall-herb fens community in the British National Vegetation Classification system Schneider 2 cells, or S2 cells, a commonly used Drosophila cell line Secondary somatosensory cortex, a brain area in the parietal cortex Sacral spinal nerve 2, a spinal nerve of the sacral segment Schedule 2, an Australian legal category assigned to drugs; See Standard for the Uniform Scheduling of Medicines and Poisons S2, the second sacral vertebrae S2 (heart sound), a sound in cardiac auscultation ATC code S02 Otologicals, a subgroup of the Anatomical Therapeutic Chemical Classification System Computing S2 (programming language) S2 Spreadsheet, by IBM in 1984 Transportation Cars Audi S2, a turbo-charged sports car Lotus Elise S2, a Lotus Elise production series of roadster automobile Porsche 944 S2, a 3l naturally aspirated Porsche 944 sports car Roads and bus routes County Route S2 (California) Expressway S2 (Poland), a southern bypass of Warsaw S2 National Highway, one of the National Highways of Pakistan S2 expressway (Shanghai), an expressway in Shanghai also known as the Hulu Expressway S2, an abbreviation for a standard single carriageway road, with a single lane going in each direction Stagecoach Gold bus route S2, a bus route in Oxfordshire, England Aviation and space Bangladesh (aircraft registration code) JetLite (IATA airline code) Focke-Wulf S 2, a 1928 German trainer aircraft Grumman S-2 Tracker, a 1952 United States Navy anti-submarine warfare (ASW) aircraft SABCA S-2, a 1926 Belgian aircraft Short S.2, a Short Brothers aircraft Strojnik S-2, motorglider S-II or S-2, the 2nd stage of the Saturn V rocket Rail Locomotives Alco S-2, a locomotive PRR S2, a unique steam turbine locomotive NER Class S2, a class of British steam locomotives Passenger services S2 (Berlin), an S-Bahn service S2 (Dresden), an S-Bahn service S2 (Munich), an S-Bahn service S2 (Nuremberg), an S-Bahn service S2 (RER Vaud), an S-Bahn service in Switzerland S2 (Rhine-Main S-Bahn), an S-Bahn service S2 (Rhine-Ruhr S-Bahn), an S-Bahn service S2 (St. Gallen S-Bahn), an S-Bahn