[webauthn] Unicode "tag" characters are deprecated for language tagging (#1642)

aphillips has just created a new issue for https://github.com/w3c/webauthn:

== Unicode "tag" characters are deprecated for language tagging ==
6.4.2. Language and Direction Encoding
https://www.w3.org/TR/webauthn-2/#sctn-strings-langdir

> The first encodes a language tag with the code point U+E0001 followed by the ASCII values of the language tag each shifted up by U+E0000. For example, the language tag “en-US” becomes the code points U+E0001, U+E0065, U+E006E, U+E002D, U+E0055, U+E0053.

The use of Unicode language tag characters for language identification is strongly deprecated by Unicode. Introducing these language tag characters on the wire is probably not desirable. Other standards have generally introduced specific encoding mechanisms, such as JSON-LD's I18N namespace, to allow language tags and direction metadata to be encoded using ASCII characters and this is preferable. This is especially that case for length-constrained fields, since the language tag characters require 4-bytes per code point in any of the Unicode encodings.

I18N is in the process of modifying our document [String-Meta](https://w3c.github.io/string-meta) to clarify the best practices in this area.

Please view or discuss this issue at https://github.com/w3c/webauthn/issues/1642 using your GitHub account


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Received on Friday, 9 July 2021 17:30:28 UTC