library_index

    OpenVMS usage:longword_unsigned
    type:         longword (unsigned)
    access:       read only
    mechanism:    by reference
    Library control index returned by the LBR$INI_CONTROL library
    routine. The library_index argument is the address of the
    longword that contains the index.

 mod_addr

    OpenVMS usage:address
    type:         quadword address
    access:       read only
    mechanism:    by 32-bit or 64-bit reference
    The address from which the Library service obtains the 64-bit
    address of where the module is mapped in memory. The mod_addr
    argument is the 32- or 64-bit virtual address of a naturally
    aligned quadword containing the virtual address location of the
    module to write to the library.

 mod_len

    OpenVMS usage:byte_count
    type:         quadword (unsigned)
    access:       read only
    mechanism:    by 32- or 64-bit reference
    The 64-bit virtual address of a naturally aligned quadword
    containing the length of the module that the Library service
    is to write into the library.

 txtrfa

    OpenVMS usage:vector_longword_unsigned
    type:         longword (unsigned)
    access:       write only
    mechanism:    by reference
    The module's record file address (RFA) of the library module
    header. The txtrfa argument is the address of the 2-longword
    array receiving the RFA of the newly created module header.