[CLEAN\]READ Buffer File /NOTRAIL [/FREQUENCY Freq] [/RANGE Min Max
Type]
When reading UV Tables, ignores any trailing column. Trailing columns
normally 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.