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

 Message        Compaq C allows the initialization of a variable with
                extern storage class.  This differs from the VAX C
                behavior.

 Description    VAX C does not allow a variable with extern storage
                class to be initialized.  Compaq C will allow this,
                even in vaxc mode.

 User Action    Be aware of this difference if you plan to compile
                the source with VAX C.