UV_FILTER /FREQUENCY

        [CLEAN\]UV_FILTER [/RESET] [/ZERO]  /FREQUENCY  F1  [...  [Fn]]  [/WIDTH
    Width]

    Specify around which frequencies the line emission should be filtered.  Fre-
    quencies  F1  to  Fn  must be in MHz. The full width of the filtering window
    around every frequency can be set by option /WIDTH.  The  optional  argument
    TYPE  indicates the type of width: FREQUENCY (in MHz), VELOCITY (in km/s) or
    CHANNEL (no unit), the default being FREQUENCY.  The default  width  is  the
    current channel width.

    Tip:  it  can  be  convenient to have a list of SIC variables containing the
    frequencies of the most intense spectral lines, e.g.
            HCO10 = 89188.52