In Emacs24 if I run the code below to define glyphs for the characters 171 and 187 the effect is different on unibyte (i.e., "coding: raw-text-unix") and non-unibyte buffers, as shown in the attached screenshot. My guess is that for some range of characteres that includes 171 and 187 - but not 15, see the screenshot - the glyph lookup is either disabled in unibyte buffers or it is done using some range translation that I wasn't able to figure out what is. Here is the test code: --snip--snip-- cat > /tmp/g <<'%%%' (progn (menu-bar-mode 0) (tool-bar-mode 0) (scroll-bar-mode -1) (defun eepitch-set-glyph (pos &optional char face) (aset standard-display-table pos (if char (vector (make-glyph-code char face))))) (if (not standard-display-table) (setq standard-display-table (make-display-table))) (defface eepitch-star-face '((t (:foreground "red"))) "Face used for the red star glyph (char 15).") (defface eev-glyph-face-green '((t (:foreground "green"))) "Face used for the green glyphs (`<<' and `>>', chars 171 and 187).") (eepitch-set-glyph ?\^O ?* 'eepitch-star-face) (eepitch-set-glyph 171 171 'eev-glyph-face-green) (eepitch-set-glyph 187 187 'eev-glyph-face-green) (insert "\n;; " 15 171 187) ) ;; Local Variables: ;; coding: raw-text-unix ;; End: %%% emacs23 -fg bisque -bg black -fn 6x13 -Q /tmp/g emacs24-from-git -fg bisque -bg black -fn 6x13 -Q /tmp/g --snip--snip-- Cheers, thanks in advance =), Eduardo Ochs eduardoochs@gmail.com http://angg.twu.net/ http://angg.twu.net/#eev P.S.: I use glyphs a lot in my personal files (see ), and a few glyphs - 3, actually - in a package that I would like to include in Emacs in a few more months or years: ... I tried to keep this first bug report quite concise, but I may have tests ready for several other related cases where the behaviors of Emacs24 were a bit unexpected to me... P.P.S.: the Emacs23 used for comparison was the standard one in Debian Squeeze, GNU Emacs 23.2.1 (i486-pc-linux-gnu, GTK+ Version 2.20.1) of 2013-01-08 on murphy, modified by Debian and the extra info for my Emacs24 from the git repository (I ran it with "-Q") follows below. In GNU Emacs 24.3.50.2 (i686-pc-linux-gnu, GTK+ Version 2.20.1) of 2013-02-11 on varda Windowing system distributor `The X.Org Foundation', version 11.0.10707000 System Description: Debian GNU/Linux 6.0.6 (squeeze) Important settings: value of $LANG: C locale-coding-system: nil default enable-multibyte-characters: t Minor modes in effect: tooltip-mode: t mouse-wheel-mode: t tool-bar-mode: t menu-bar-mode: t file-name-shadow-mode: t global-font-lock-mode: t font-lock-mode: t blink-cursor-mode: t auto-composition-mode: t auto-encryption-mode: t auto-compression-mode: t line-number-mode: t transient-mark-mode: t Load-path shadows: None found. Features: (shadow sort gnus-util mail-extr emacsbug message format-spec rfc822 mml easymenu mml-sec mm-decode mm-bodies mm-encode mail-parse rfc2231 mailabbrev gmm-utils mailheader sendmail rfc2047 rfc2045 ietf-drums mm-util mail-prsvr mail-utils time-date tooltip ediff-hook vc-hooks lisp-float-type mwheel x-win x-dnd tool-bar dnd fontset image regexp-opt fringe tabulated-list newcomment lisp-mode register page menu-bar rfn-eshadow timer select scroll-bar mouse jit-lock font-lock syntax facemenu font-core frame cham georgian utf-8-lang misc-lang vietnamese tibetan thai tai-viet lao korean japanese hebrew greek romanian slovak czech european ethiopic indian cyrillic chinese case-table epa-hook jka-cmpr-hook help simple abbrev minibuffer loaddefs button faces cus-face macroexp files text-properties overlay sha1 md5 base64 format env code-pages mule custom widget hashtable-print-readable backquote make-network-process dbusbind inotify dynamic-setting system-font-setting font-render-setting move-toolbar gtk x-toolkit x multi-tty emacs)