VMS Help RTL Routines, LIB$, LIB$DEC_OVER, Argument  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 new-setting

    OpenVMS usage:longword_unsigned
    type:         longword (unsigned)
    access:       read only
    mechanism:    by reference

    New decimal overflow enable setting. The new-setting argument is
    the address of an unsigned longword that contains the new decimal
    overflow enable setting. Bit 0 set to 1 means enable; bit 0 set
    to 0 means disable.