Re: Latin ligatures and Unicode

From: John Cowan (
Date: Mon Dec 27 1999 - 11:41:31 EST

Eberhard Pehlemann wrote:

> 1. As I pointed out in my reply to John Jenkins, there are cases where the software will
> not be able to determine ligation correctly. (The "Wachstube" example) In these cases
> the author MUST explicitly specify ligation. So Unicode MUST provide means to do so

I agree.

> 2. Software can do a lot, but does it do so? I am pretty sure that there does not exist
> a single text editor that handles all blackletter ligatures.

It is not text editors (which deal in characters) that should handle ligatures, but
rather font rendering engines (which map characters to glyphs) which should do so.

> 3. With the OpenType or related fonts every font designer can offer ligature shapes in
> his fonts. I would like to do so for the (few?) people that like blackletter fonts.

Just so.

> 4. What about portability and exchangeability of text fragments, if one program handles
> ligatures and another does not?

This is meaningful only if applications know about ligatures, as IMHO they should not.
Applications should let users specify ZWL and ZWNL, and leave the rest up to the font
rendering engine.

> The experts have to decide whether ZWJ and ZWNJ should be used for this purpose or not,

Though not an expert, I believe the answer is "no".

> and if there also is a need for a ZWNL in addition to a ZWL character.

I believe this is needed. Absent an explicit ZWNL, a font should be able to ligature
when it believes it should, so that routine "ff" ligatures can be created
while allowing corner cases like "shelfful", where a ligature is probably
undesirable, to be forcibly unligatured.

> Maybe, ligation in the arabic and indic scripts has been a problem more urgent to be
> solved by Unicode than ligation in the latin script.

Actually, control of ligation proper (as opposed to character shaping) in Arabic, is not
yet provided by Unicode either.

However, I now think it was a mistake for Unicode to use ZWJ/ZWNJ for Indic scripts,
since this *is* a case of ligation rather than shaping.


Schlingt dreifach einen Kreis vom dies! || John Cowan <> Schliesst euer Aug vor heiliger Schau, || Denn er genoss vom Honig-Tau, || Und trank die Milch vom Paradies. -- Coleridge (tr. Politzer)

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