On Mon, 19 Feb 2018 20:02:28 +0100 Philippe Verdy via Unicode <firstname.lastname@example.org> wrote:
> This pair of punctuation should have been considered since long as > common punctuations (independantly of their assigned names), i.e. > assigned the script property "Comn" and not "Deva". I don't see why > they could not be used in non-indic scripts (because they are not > semantically equivalent to Latin punctuations in their use). They currently both have sc=Common, so common sense prevails here. > I can easily imagine valid uses cases even in Latin, Greek or > Cyrillic to properly translate poems, religious texts, or citations... They have had scx ∍ Latn, but no longer. It may be because CLDR lacks sa_Latn; perhaps someone will claim that that the dandas and double dandas I've seen in Sanskrit verses in Latin script are actually something else. > Their presence in fonts designed for Indic scripts should be > mandatory or strongly recommanded... They're generally not necessary for scripts in whose encoding Michael Everson has had a significant hand. He defines script-specific dandas. Tai Tham has two such pairs! >... (just like the mapping of SPACE, > NBSP, dotted circle or blank square, and a few others listed in > OpenType development documentation), meaning that given their > "Common" script property we don't need to test their presence to > compute a script coverage (any other font available could also be > used by renderers to insert their own glyph if some Indic fonts are > ever defective for forgetting to map glyphs to them, just like a > renderer is allowed to substitute or infer a synthetized glyph for > the dotted circle or blank square, or any whitespace variant, if ever > they are not mapped, using only the basic font metrics to scale the > glyph or infer a suitable advance width/height; the renderer just > needs to look at the generic font metrics providing average width and > heights and relative position of the baselines in the em-square). Microsoft Word and the USE document the use or recommendation for quite a few such shapes and special letters. They make ulUnicodeRange rather unreliable. Note, however, that ulUnicodeRange works by Unicode range, not script. Richard.