Re: ZWJ and Latin Ligatures (was Re: (long) Re: Chromatic font research)

From: John Hudson (
Date: Thu Jul 04 2002 - 12:53:03 EDT

At 14:31 6/30/2002, James Kass wrote:

>Sounds like a giant step backwards from Unicode 3.0.1 (March 2002)
>(see section "Controlling Ligatures")
>This page clearly states that ZWJ is proper for controlling the
>formation of Latin ligatures and even uses f+ZWJ+i as an example.
>Unicode 3.1 (May 2002) uses the same examples:
>Can you please point me to a URL for Unicode 3.2 ligature control?
>This link (March 2002):
>...glosses over Latin ligatures suggesting that mark-up should be
>used in some cases and ZWJ in others.
>Becuase of the reasons cited in that last link, IMHO ligature control
>is best performed by the author of a document and ZWJ still seems
>to be the most straightforward method.

Well, we need and have (in OpenType and AAT) a general purpose mechanism
for typesetting texts employing ligatures as deemed fit by the professional
typographer. The expectation of such a mechanism is that layout is applied
to 'normal' text to render that text according to the norms of particular
typographic traditions, publishing house styles, etc.. It should not be
necessary to edit the text, inserting ZWJ all over the place, in order to
achieve this result.

There are, however, kinds of documents in which the presence or absence of
ligatures is best determined by the author of the document, and for that
reason the ZWJ provides a means for the author to specify ligation in plain
text. But it seems to me that such documents are the exception rather than
the norm (a particular set of ligatures involving the lowercase f have been
a normative aspect of European typography for more than 500 years; in my
profession they are not considered optional or discretionary in the setting
of running text at typical sizes). Documents using ZWJ can only be reliably
rendered in particular fonts. For example, there is no reason why I should
not include the sequence 'p ZWJ q' in a document, but unless I have a font
containing a pq ligature I will not be able to render the sequence as
intended by the author.

John Hudson

Tiro Typeworks
Vancouver, BC

Language must belong to the Other -- to my linguistic community
as a whole -- before it can belong to me, so that the self comes to its
unique articulation in a medium which is always at some level
indifferent to it. - Terry Eagleton

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