The parameter compactness is set to C or D if
respectively a galaxy was reported as beeing "compact" or "diffuse" in
the litterature or in catalogues.
This parameter has been determine for only a fraction of the galaxies in
the database and therefore the absence of compactness does not
indicate that a galaxy is neither "compact" nor "diffuse".
There are 4874 galaxies with compactness=D and 4304 with
compactness=C in the database (May 2003 version).