/sys$common/syshlp/helplib.hlb CC, Messages, VLAEXTENSION  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 Message        <Context> variable length arrays are a new feature in
                the C99 standard.  Other C compilers may not support
                this extension.

 Description    This is a new language feature in the C99 revision of
                the standard.  While having a standard specification
                for portability, the feature may not yet be available
                in all of the compilers you use.

 User Action    Determine whether or not the use of this feature will
                cause portability problems for this code.