[2] Language enablement index, 2020-08-21T16:05:14.000Z, 2020-10-18T07:04:53.736Z https://w3c.github.io/typography/
[4] International text layout and typography index (2017-02-09 16:20:37 +09:00) https://www.w3.org/TR/2017/WD-typography-20170209/