invo_context

    OpenVMS usage: invo_context_blk
    type:          structure
    access:        read
    mechanism:     by reference

    Address of a valid invocation context block.

 index

    OpenVMS usage: index
    type:          longword
    access:        read
    mechanism:     by value

    Index into the IREG array of the invocation context block.

 gr_copy

    OpenVMS usage: integer value
    type:          quadword
    access:        write
    mechanism:     by reference

    Address of a quadword to receive the value from the invocation
    context block.