VMS Help DECTPU, USER, Arguments  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 integer

    OpenVMS usage:longword_unsigned
    type:         longword (unsigned)
    access:       read only
    mechanism:    by reference
    First parameter to the built-in procedure CALL_USER. This is an
    input-only parameter and must not be modified.

 stringin

    OpenVMS usage:char_string
    type:         character string
    access:       read only
    mechanism:    by descriptor
    Second parameter to the built-in procedure CALL_USER. This is an
    input-only parameter and must not be modified.

 stringout

    OpenVMS usage:char_string
    type:         character string
    access:       modify
    mechanism:    by descriptor
    Return value for the built-in procedure CALL_USER. Your program
    should fill in this descriptor with a dynamic string allocated by
    the string routines (such as LIB$SGET1_DD) provided by the Run-
    Time Library. The DECTPU editor frees this string when necessary.