Xemacs notes

      Xemacs doesn't seem to care about foundries. This is a pain if
      you want it to use misc-fixed but it insists on the pig-ugly
      Sony misc instead. Customize doesn't let you select a foundry at
      all, and Emacs.default.attributeFont seems to ignore the foundry
      too. Found this hack on the Xemacs mail archives:

(define-specifier-tag 'a-unique-tag)
(set-face-font 'default

Seems to work.

Wait, scratch that. .Xdefaults does work -- but for some reason, if
you select the iso10646 encoding (rather than * as here) it switches
to the Sony misc font. Curious. I'll just have to live without