Language and text direction for labels?

[tidoust]

The spec indicates that media metadata specification may be displayed in the platform UI. This includes a number of text-based properties such as title, artist, album, and chapter information.

These properties are defined as DOMString. First guideline in the internationalization checklist is "ensure that there's [...] support for basic things such as language and text direction".

Should the string properties be completed with language and text direction? Text direction seems relevant for display in particular.