VMS Help CC, Run-time functions, toupper, _toupper  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  Convert their argument, a character, to uppercase.  If the argument
  is not a lowercase character, it is returned unchanged.

  Syntax:

       #include <ctype.h>

       int toupper(int character);
       int _toupper(int character);