context

    OpenVMS usage:context
    type:         longword
    access:       modify
    mechanism:    by reference
    Value identifying the data stream that DCX$ANALYZE_DONE deletes.
    The context argument is the address of a longword containing this
    value. DCX$ANALYZE_INIT initializes this value; you should not
    modify it. You can define multiple context arguments to identify
    multiple data streams that are processed simultaneously.