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

  Creates a directory.

  Syntax:

       #include <stat.h>

       int mkdir(const char *dir_spec, mode_t mode); (POSIX-1)

       int mkdir(const char *dir_spec, mode_t mode,...); (Compaq C
       Extension)

  where the ...  represents the following optional arguments.  These
  arguments have fixed position in the argument list, and cannot be
  arbitrarily placed.

   o  unsigned int uic

   o  unsigned short max_versions

   o  unsigned short r_v_number