18.7.25      CLEAN_RESIDUAL

An integer code indicating what the Clean image will contain. Its usage is reserved for tests or specific algorithm using the basic CLEAN as an engine.

 -1    The CLEAN image contains only the Clean components, not convolved
         with the Clean beam.
  0    Normal behaviour:  Convolve Clean components with Clean beam and
         add the residuals.
 +1    Convolve Clean components, but do not add the residuals.