Concerning the use of ZWJ to request ligation in the Latin script (and, less contentiously, the use of ZWNJ to prevent it), many -- including some experts and UTC members -- have stated that ZWJ should only be used in exceptional circumstances, or when the requested ligature is necessary grammatically or orthographically instead of stylistically (however that is determined).
I'm starting to see why I disagree so strongly with this position. It's not that I'm eager to "pepper" my text with ZWJs or to require other writers to do the same, or even that I think modern English text in most circumstances really requires much more than the basic f-ligatures. No, what bothers me is that the ZWJ/ZWNJ ligation scheme is starting to look just like the DOA (deprecated on arrival) Plane 14 language tags. In each case, Unicode has created a mechanism to solve a genuine (if limited) need, but then told us -- officially or unofficially -- that we should not use it, or that it is "reserved for use with special protocols" which are never defined or mentioned again. I think I've lost the battle regarding Plane 14 tags -- though I can't promise I'll never use them in plain text without those mysterious "special protocols" -- but the fight for ZWJ ligation continues. The UTC may have "intended" that ZWJ ligation be used only in rare and exceptional circumstances, but UAX #27, revised section 13.2 doesn't say that. It says that ZWJ and ZWNJ *may be used* to request ligation or non-ligation, and that "font vendors should add ZWJ to their ligature mapping tables as appropriate." It does acknowledge that some fonts won't (or shouldn't) include glyphs for every possible ligature, and never claims that they must (or should). It specifically does *not* say that ZWJ ligation is to be restricted to certain orthographies, or to cases where ligation changes the meaning of the text. As Michael and Asmus have pointed out, without ZWJ ligation we will continue to see numerous, very serious proposals to add more ligated presentation forms to Unicode. Is that what we want? Not everyone will buy into the notion that AAT and OpenType will automagically handle all ligation scenarios. ZWJ/ZWNJ for ligation control is part of Unicode. It is not always the best solution, but it is *a* solution, and should be available to the user without restriction or discouragement. -Doug Ewell Fullerton, California
