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

    The Phase IV NCP ZERO command has no Phase V equivalent.  Instead,
    please use to the NCL SNAPSHOT command to observe a change in
    counters between two points in time.

    The reason Phase V does not permit zeroing of the counters over
    the life of an entity is to enable multiple directors to concurrently
    monitor counters.  In other words, unlike Phase IV, Phase V does not
    permit one network manager to zero counters while another manager is
    still watching them.