It is possible (but not improbable) for the value of an
    attribute to change between the time that the attribute
    value is tested against the with clause value and the time
    that the directive is actually issued to the entity. This
    limitation can lead to cases such as the following:

    ncl> show 0 session control port *, with send queue > 0

    Node 0 Session Control Port %XCC354000
    AT 1994-11-13-16:32:03.249-05:00I0.269

    Status

       Send Queue = 0

    In this case, the attribute briefly goes non-zero, then
    immediately returns to zero again. Unfortunately, the
    attribute changed value between the time that it was
    sampled by the entity filtering software in the CML (CMIP
    Management Listener) and the time that the Show directive
    was issued to that entity instance. This is generally
    not a problem. Most attributes are stable enough that this
    rarely happens.