va

    OpenVMS usage address
    type          quadword (unsigned)
    access        read only
    mechanism     by value
    Virtual address of interest.

 img_info

    OpenVMS usage address
    type          quadword (unsigned)
    access        write only
    mechanism     by reference
    Pointer to return addr of LDRIMG or IMCB block.

 subimg_info

    OpenVMS usage address
    type          quadword (unsigned)
    access        write only
    mechanism     by reference
    Pointer to return addr of ISD_OVERLAY or KFERES.

 offset

    OpenVMS usage quadword_unsigned
    type          quadword (unsigned)
    access        write only
    mechanism     by reference
    Pointer to address to return offset from image.