Note, that as well as for bars, the detection of a ring is subject to
strong observational effects (bandpass, spatial resolution, ...).
Only a small fracteion of the largest galaxies in the database have been
searched for a ring and the parameter ring is strongly biased.
There are 3168 galaxies with ring=R (in the May 2003 version).
The parameter bar reports another
morphological particularity of the galaxies: The presence of a bar.