c9 | Disambiguation

C9, C09 or C-9 may refer to:

C9, an international technology based solutions provider C9 Operations based in Pompano Beach, Florida
C9, an international standard paper size (40×57 mm), defined in ISO 216
C9, a brand of performance apparel exclusively sold at Target stores.
C9 engine, by Caterpillar Inc.
C9, a global group of nine leading economists based in Zürich, Switzerland
C9 League, an association of nine top Chinese universities
C9, an extremely high musical note five octaves above Middle C.
ATC code C09 Agents acting on the renin-angiotensin system, a subgroup of the Anatomical Therapeutic Chemical Classification System
C09, Malignant neoplasm of tonsil ICD-10 code
C-9, A Counter-Strike short code for "Enemy Down!"
Just some guy who spends too much time on Twitter, LiveJournal, and Facebook. He also likes chocolate.

Transportation

Cierva C.9, a 1927 British experimental autogyro
HMS C9, a C-class submarine of the Royal Navy
McDonnell Douglas C-9 (C-9A Nightingale/C-9B Skytrain II), a transport aircraft of the United States Air Force (Nightingale) or U.S. Naval Reserve and United States Marine Corps (Skytrain II). It is the military version of McDonnell Douglas DC-9
USS Montgomery (C-9), a protected cruiser of the United States Navy
C9, the IATA code for Cirrus Airlines
Just some guy who geeks out about airlines and airplanes.