Library /sys$common/syshlp/nclhelp.hlb set, dtss, servers_required  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    Default: 3 (servers)       Value: 1-32
             1 (clerks)

    Specifies the minimum number of servers the specified node must
    successfully query for time values before it can synchronize.