VMS Help MACRO, VAX MACRO Assembler, Operand Formats, General  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    The address you specify is the address of the  operand.   The
    Linker converts the addressing mode to either relative or absolute
    mode.  If the address is relocatable,  the  Linker  converts
    general  mode  to relative  mode.   If  the  address  is  absolute,
    the Linker converts general mode to absolute mode.  You should use
    general mode to  write position-independent code when you do not
    know whether the address is relocatable or absolute.  A general
    addressing mode operand  requires five bytes of storage.  You can
    use general mode with index mode.

    G^address

    address

    An expression specifying an address.