Accessibility: lang="sa-Latn"

[michael-roe]

This is a feature request to allow "-Latn" at the end of a language attribute. This is typically used for languages that can be written in several different scripts (e.g. Sanskrit) to indicate the Latin alphabet is being used.

Probably, most text to speech ereaders don't support this, but we ought to provide the attribute for the benefit of future software.

At the moment, ebookmaker gives me a warning:

WARNING:root:invalid lang attribute sa-Latn

[HendrikBK]

In my opinion, it would be preferred to allow any of these codes to be inserted, instead of specifically allowing Latn.

[Hopkins1]

As mentioned above, there are more script tags beyond "Latn". In particular I'd like to see "zh-Hans" and "zh-Hant" for the Chinese language.

"Hans" refers to Chinese using the Simplified script and "Hant" refers to the Traditional script. Web browsers (tested on Chrome, Firefox, and Opera) as well as EPUB readers (tested on Kindle, Kobo, iPad) change the positioning of the punctuation based on the script tag. I find it easier to read traditional text when the "Hant" typography is used. The punctuation is kept slightly more separated from the Chinese characters.

The eBook industry also wants to see script tags used. For example, Apple requires either "zh-Hans" or "zh-Hant" for any submissions to Apple Books (Apple Books Asset Guide):

Note: For Chinese language books, you must specify both the language (zh) and the script (Hans or Hant) portions of the language code. The language code for Simplified Chinese is zh-Hans and the code for Traditional Chinese is zh-Hant. The code must be specified in both the book’s OPF file and in the metadata using the tag.

[michael-roe]

I agree if we’re going to add this we should also support zh-Hans etc.