Re: 23.0.50; `mode-name' variable docs out of date WRT features

[Richard Stallman]

    Recent Emacs snapshots have extended the `mode-name' variable, so that
    constructs such as

      '(sgml-xml-mode "XML" "SGML")

We never discussed the question of using this variable that way.  I
think someone just noticed that this value works -- in the mode line,
at least -- and started using it.

But this value doesn't work everywhere.  There are files (bookmark.el
is one) that expect the value to be a string, as the manual says.

I think that the change in sgml-mode.el needs to be backed out.
Stefan, could you redo that differently, then ack?