APPLY /FLAG

        [CALIBRATE\]APPLY [AMPLI|DELAY|PHASE [Gain]] /FLAG [Threshold]

      Apply gain solution (in AMPLITUDE, DELAY or PHASE) and flag data without a
    corresponding valid gain solution.

      If the Threshold argument is present, all data with a correction exceeding
    that threshold are also flagged. This can be useful to filter  out  antennas
    that  have unstable gains. A threshold of 90 degrees in phase, or 1.3 in am-
    plitude may be appropriate.

    The optional Gain argument has no effect on the Threshold: it is always  the
    gain value in the CGAINS array that is compared to the Threshold.

      USEFUL TRICK: If you forgot to flag the data while applying the self-cali-
    bration gain solution, you can still do it a posteriori without changing the
    amplitude and/or phase by using command
              APPLY MODE 0 /FLAG Threshold
where MODE is any of AMPLI, DELAY or PHASE.