[Groff] Obsolete Df command?

[Bernd Warken]

The groff_out man page documents the command

      Df n\n Set the shade of gray to be used for filling  solid
              objects  to  n;  n must be an integer between 0 and
              1000, where 0 corresponds solid white and  1000  to
              solid  black,  and  values in between correspond to
              intermediate shades of gray.  This applies only  to
              solid  circles,  solid ellipses and solid polygons.
              By default, a level of 1000 will be used.  Whatever
              color  a  solid  object  has,  it should completely
              obscure everything beneath  it.   A  value  greater
              than  1000  or  less  than 0 can also be used: this
              means fill with the shade of gray that is currently
              being  used for lines and text.  Normally this will
              be black, but some drivers may  provide  a  way  of
              changing this.


This is now obsoleted by the command `DF g grey' command.
So should the Df command be removed, or shall the existing 
handling be kept, or should it be mapped to the DFg command? 

Bernd Warken