VMS Help CC, Messages, LONGLONGTYPE  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 Message        <Context> type "<type>" is a new feature in C99.

 Description    On some platforms, Compaq C will accept the
                [unsigned] long long type as a way to declare
                [unsigned] 64-bit integers.  The long long int type
                is a new feature of C99 and other compilers might not
                accept this declaration.

 User Action    Be aware of this portability concern.