auto -- C Keyword

Note an automatic variable

auto is an abbreviation for an  automatic variable. This is a variable that
applies  only  to the  function  that  invokes it,  and  vanishes when  the
functions exits.   The word auto  is a C  keyword, and must not  be used to
name any function, macro, or variable.

See Also

C keywords,
extern,
static,
storage class,
ANSI Standard, §6.5.1

© 2012 by Stephen A. Ness