VMS Help CC, Messages, DEFINOTHER1  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 Message        The external variable "<name>" was defined as an
                external function in another module of this
                compilation at <where>.

 Description    In a compilation where interfile optimization has
                been selected (-ifo on UNIX, /PLUS_LIST_OPTIMIZE on
                OpenVMS), the compiler has detected a name with
                external linkage defined as a variable in one
                compilation unit and a function in another.

 User Action    Remove or rename one of the definitions.