From a99ea1e130249680655672056e1ba2feab8f83fe Mon Sep 17 00:00:00 2001
From: Christian Liebel
such as fonts, styling, hyphenation, or text-to-speech voices for accessibility.
- A language tag is a string that matches the - production of a `Language-Tag` defined in the [[BCP47]] - specifications (see the IANA - Language Subtag Registry for an authoritative list of possible - values). That is, a language range is composed of one or more - subtags that are delimited by a U+002D HYPHEN-MINUS ("-"). - For example, the '`en-AU`' language range represents English as - spoken in Australia, and '`fr-CA`' represents French as spoken in - Canada. Language tags that meet the validity criteria of [[RFC5646]] - section 2.2.9 that can be verified without reference to the IANA - Language Subtag Registry are considered structurally valid. + A language tag is a [=string=] that matches the production + of a well-formed `Language-Tag` defined in [[BCP47]]. +
++ Language tags are case-insensitive. Examples of language tags include + '`fr`' (French), '`en-AU`' (English as spoken in Australia), or + '`zh-Hans-CN`' (Chinese as written in the Simplified Han script as + spoken in China).
To process the `lang` member, given [=ordered map=]