Am 1999-08-23 um 0:22 H hat Markus Kuhn geschrieben:
> Would it be possible to add to LATIN SMALL LETTER SHARP S U+00DF a
> cross-reference to U+0073 + U+017f in the Unicode 3.0 book? [...]
> Making the reader aware that the sharp s derives
> historically from a U+0073 + U+017f ligature will hopefully lead font
> designers without experience in German typography to coming up with more
> appropriate glyphs than the common beta variant.

Actually, the Sharp-S is derived from a ligature of U+017F followed by U+0292,
and I suggest to add a remark to U+00DF saying so.

In medeaval writing of German, U+0292 denoted a voiceless S sound, which
had replaced the T sound during the 2nd (German) sound-shift (aka Grimm's
law). Later (about 14th century), the U+0292 glyph was used for the German Z
character (pronounced ts), and the former U+0292 was replaced with SZ
(S plus U+0292, i. e. an U+0292 to be pronounced like an S). In German hand-
writing and print, S was written with two different characters (Round S U+0073,
and Long S U+017F, depending on particular spelling rules). According to these
rules, the above mentioned SZ was regularly written as U+017F U+0292, which
formed a ligature and eventually evolved into U+00DF, a character named "Eszet"
(in reminiscence of its genesis). E. g. "Teuerdank", printed in 1517, of
which I own a facsimile, uses U+0073 and U+017F for (modern) S, U+0292 for
(modern) Z, and a ligature of U+017F and U+0292, i. e. U+00DF, for (modern) ß
("modern" to be understood modulo later spelling reforms, of course). And so
did all Fraktur prints until the early 20th century, as far as I have seen
(and if memory does serve me alright -- I have not checked this detail).

Cf.
  Jacob Grimm: "Deutsches Wörterbuch", vol. 8,  fasc. 8 (1963),
  col. 1573 and 1574.

In German hand-writing and print (Fraktur), the U+017F glyph has a descender
(in contrast to the example given in the Unicode Standard 2.0). So have
U+0292, and the resulting ligature.

In roman print (Antiqua), U+017F usually does not have a descender (as the
example glyph given in the Unicode Standard). Consequently, the U+0292 part
of the ligature is raised to the ground line, resulting in the example glyph
given for U+00DF.

In some Antiqua fonts, however, the right part is rather derived from the
U+0073 (Round S) glyph, as in the fonts Albertus medium (Hewlett-Packard),
Book Antiqua (Hewlett-Packard), Bookman Old Style (Monotype), Univers
(Hewlett-Packard), and less conspicuously in Arial (Monotype) that comes
with every MS-Windows installation. Also the renowned typographer Jan
Tschichold, has adopted the view (in contrast to the history established by
J. Grimm, and elsewhere) that "ß" were derived from a ligature of Long-S and
Round-S (U+017F and U+0073), and has designed his fonts, accordingly.

Best wishes,
   Otto Stolz