What does .C stand for?

What does .C mean?

C	Commitment Business » Positions
C	Carbon Academic & Science » Chemistry
C	Christ Community » Religion
C	Cardinal Business » Positions
C	Core Computing » Hardware
C	Command Computing » Assembly
C	Cleveland Regional » States
C	Cited Community » Media
C	Collect Computing » Telecom
C	Citizen Governmental » US Government
C	Consumption Miscellaneous » Food
C	Calculated Academic & Science » Mathematics
C	Counsel Business » General
C	Columbus Regional » States
C	Cervical Medical » Physiology
C	Complexity Business » Products
C	Cure Medical » Laboratory
C	Coordination Business » General
C	Conventional Governmental » Military
C	Championship Community » Sports
C	Cloud Academic & Science » Meteorology
C	Colored Miscellaneous » Colors
C	Cher Miscellaneous » Names and Nicknames
C	Cod Academic & Science » Ocean Science
C	Coupe Business » Products