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

    OpenVMS usage:longword_unsigned
    type:         longword integer (unsigned)
    access:       write only
    mechanism:    by value

    The old decimal overflow enable setting (the previous contents of
    SF$W_PSW[PSW$V_DV] in the caller's frame).