Localized tags, categories, etc. It needs to be possible, for example, to say "the tag 'Foo' in English is equal to the tag 'Le foo' in French". This would allow a list of articles tagged "Le foo" to list both articles in French and in English for articles not yet translated.

I think this is a new feature, at least with respect to MindTouch

This is still a desired feature. Tags are not translated. Instead, a new tag is created, where the tag name is a translation of the English tag. There's no link between the "English" tag and the "Translated" tag. This causes real problems when the tag is used for organizing content: * Content-collecting KumaScript macros like {{SubpageMenuByCategories}} need to be passed per-locale tag variants, or localizers have to set both the English and "translated" tags. As reported in bug 1215445, this means that a page like https://developer.mozilla.org/en-US/docs/MDN/Contribute/Tools is fully populated in English, sparsely populated in French ( https://developer.mozilla.org/fr/docs/MDN/Contribute/Tools), and manually copied in Chinese (https://developer.mozilla.org/zh-CN/docs/Project:MDN/Tools). Reliable tag identifiers are a requirement to making these macros more effective. * Search categorizes content by tags. This is a bad way to categorize content, and it also makes translated content even less searchable than English content. A strong tag identifier would improve non-English site search (but not as much as re-writing search) * Various "Doc Status" tools on MDN rely on tagging, and are broken by default when the localization team doesn't apply English tags to new pages. * Tags that only differ by an accent character, such as the French "Référence" versus "Reference", are not well supported by MySQL. This was handled with a custom collation in the past, but this was removed in bug 1391084 to allow using unmodified MySQL. It is currently impossible to "Translate" these tags into some languages. A better system would be: * Use the English tag (such as "Reference") or the non-translated tag (such as "HTML", "CSS") as the strong identifier. * Mark a tag as localizable ("Reference") or not localizable ("HTML", "CSS"). * Pass the localizable strings to Pontoon for translation. * Apply the translation in interfaces, such as rendering or editing. This system would be much easier to implement if there were a limited set of tags that were controlled in source control, rather than in a database, but if rapid addition of tags is a requirement, then a database-to-Pontoon processing step could be added, similar to search topics (which is also a bad idea).

MDN Web Docs' bug reporting has now moved to GitHub. From now on, please file content bugs at https://github.com/mdn/sprints/issues/ and platform bugs at https://github.com/mdn/kuma/issues/.