From en.wikipedia.org:
[wiktionary] SO2 or SO<SUB>2</SUB> may refer to: [TOC right]
** Science
- Sulfur dioxide (SO <sub> 2 </sub> ), a colorless gas with a pungent smell - Sulfonyl group (R-SO <sub> 2 </sub> -R), a functional group found primarily in sulfones, or a substituent - SO(2), special orthogonal group of degree 2 in mathematics - Oxygen saturation (SO <sub> 2 </sub> ), the concentration of oxygen dissolved in a medium - S2 (star) or S0–2, a star near the central black hole at the center of the Milky Way - 2015 SO <sub> 2 </sub> or 2015 SO2, an Aten asteroid
** Military and police
- SO2, a staff officer of the second class, often a commissioned officer of lieutenant commander, major or squadron leader rank - SO2, a London Metropolitan Police Specialist Operations command division - Special Operations 2 – Operational, of the British, World War II Special Operations Executive
** Other uses
<!--* _Star Ocean 2_, a video game (fails WP:DABACRO)-->
- _SO2_ (album) , a 2010 album by Shinichi Osawa
** See also
[so2]
- Oxygen saturation (medicine) (SaO <sub> 2 </sub> , SvO <sub> 2 </sub> , StO <sub> 2 </sub> , SpO <sub> 2 </sub> ) - [lookfrom] - [intitle] - Soso (disambiguation) - Soo (disambiguation) - SO (disambiguation) [Letter-Number Combination Disambiguation]