I think it would be useful to add a new use case: the rendering of punctuation marks (although I'm not sure which section is the best for it).
As an example, many Chinese punctuation marks and Western punctuation marks share code points, but if the text is not labelled as Chinese, the glyphs of punctuation marks will not match the requirements for Chinese text layout.
For example:
U+2018 LEFT SINGLE QUOTATION MARK [‘], U+2019 RIGHT SINGLE QUOTATION MARK [’], U+201C LEFT DOUBLE QUOTATION MARK [“], and U+201D RIGHT DOUBLE QUOTATION MARK [”] are non–full-width in Latin fonts, but are full-width in Chinese fonts.
U+2E3A TWO-EM DASH[⸺], U+2014 EM DASH [—], U+2026 HORIZONTAL ELLIPSIS […], and U+2013 EN DASH [–] should be vertically centred, but they are not in most Latin fonts.
[source] (https://www.w3.org/International/articles/lang-bidi-use-cases/) [en]
I think it would be useful to add a new use case: the rendering of punctuation marks (although I'm not sure which section is the best for it).
As an example, many Chinese punctuation marks and Western punctuation marks share code points, but if the text is not labelled as Chinese, the glyphs of punctuation marks will not match the requirements for Chinese text layout.
For example:
U+2018 LEFT SINGLE QUOTATION MARK [‘],U+2019 RIGHT SINGLE QUOTATION MARK [’],U+201C LEFT DOUBLE QUOTATION MARK [“], andU+201D RIGHT DOUBLE QUOTATION MARK [”]are non–full-width in Latin fonts, but are full-width in Chinese fonts.U+2E3A TWO-EM DASH[⸺],U+2014 EM DASH [—],U+2026 HORIZONTAL ELLIPSIS […], andU+2013 EN DASH [–]should be vertically centred, but they are not in most Latin fonts.U+00B7 MIDDLE DOT [·]should have the same width or half the width of a Han character, but they are not in most Latin fonts.