- From: fantasai <fantasai.lists@inkedblade.net>
- Date: Mon, 20 Feb 2017 22:21:58 -0500
- To: John Hudson <john@tiro.ca>, Jonathan Kew <jfkthame@gmail.com>, www-style@w3.org
On 02/03/2017 07:52 PM, John Hudson wrote: > On 03/02/17 16:07, fantasai wrote: >> I'd like to check with John Daggett on this point... in the meantime, >> what's the use case for having one font use one language value and a >> different font use a different one--is that ever a thing that happens? > > The first use case is OpenType fonts with different Language System coverage, one of which might be suitable for the document > language without that language being included in the font Language System coverage. My usual example for this is a document in > Macedonian being displayed using a font that contains an SRB (Serbian) Language System but not an MKD (Macedonian) Language > System. This is not unusual, as font developers at the time such a font is made might only have reliable information about > specific language typographic norms, e.g. Serbian, and not be aware that the same norms are suitable for Macedonian. > > The second use case arises from the fact that an OpenType Language System tag is not, in fact, a natural language tag directly > analogous to a document language tag. An OT Language System tag in combination with an OT Script tag, indicates a particular > typographic form of a writing system. In some cases, this can be mapped directly to a document language tag, in some cases it > might be better mapped to a locale, and some registered Language System tags indicate notation systems that are not specific > to any individual language. So, the two phonetic notation system tags for IPA and Americanist transcription — IPPH and APPH, > respectively — will be essential for enabling appropriate phonetic forms of some Greek letters that in a font may differ from > the default Greek alphabet style. This is only possible if authors are able to directly specify the appropriate OT Language > System tags independently of document language tagging. > > There is third use case, but it is very peculiar, and I don't think I've actually seen a font built in this way: it is > possible that a combination of OT Script and Language System tags can be used to identify a typographic convention for a > script that is particular to a locale. So, for example, if one examines German and French editions of classical Greek texts of > the 19th Century, one observes fairly regular and differing conventions regarding use of the long and short forms of the > letter beta (I forget the exact conventions; I recall that one uses the long form only at the beginning of a word). These > conventions could be captured in an OT font, using contextual substitutions under particular Language System tags, in such a > way that text in Greek characters (<grek> Script tag) could be processed according to either FRA (French) or DEU (German) > Language System. In that case, the Language System tag isn't indicating the document language — Greek — at all, but rather a > convention for Greek typography associated with French or German publishing conventions. I think only the first one is actually an answer to my question, but the other scenarios are interesting to have documented here in any case. :) ~fantasai
Received on Tuesday, 21 February 2017 19:39:58 UTC