VMS Help LINK, Qualifiers, /VAX  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    Directs the linker to produce an OpenVMS VAX image. The default
    action, when neither /ALPHA nor /VAX is specified, is to create
    an OpenVMS VAX image on an OpenVMS VAX system and to create an
    OpenVMS Alpha image on an OpenVMS Alpha system.