READ /NOTRAIL

        [CLEAN\]READ  Buffer  File  /NOTRAIL  [/FREQUENCY  Freq] [/RANGE Min Max
    Type]

    When reading UV Tables, ignores any trailing column. Trailing  columns  nor-
    mally  appear for mosaics. However, ALMA sometimes uses known proper motions
    to shift (by small amounts) phase centers  between  two  observing  periods,
    yielding  pseudo-mosaics with tiny (in general insignificant) displacements.
    The /NOTRAIL option allows to ignore these details.