C<default> to indicate that the default-colour escape sequence is to be
used), C<bg> is the colour code used as default background colour (or the
string C<default>), and C<xpm> is the string C<default> if @@RXVT_NAME@@
-was compiled with XPM support. Libraries like C<slang> can (and do) use
-this information to optimize screen output.
+was compiled with XPM support. Libraries like C<ncurses> and C<slang> can
+(and do) use this information to optimize screen output.
=item B<WINDOWID>