These options are not new and date back to when were collaborating with popcorn.js to display dynamic content on the videos.
over 9 years ago
Thank you for the explanation: I probably skipped them in the long language list so far. I noticed them 2 days ago because someone made "Metadata: Geo" subtitles for a (private) video I was looking at 2 days ago. Actually, just a second set of English subs.
Several new languages have been added to the Amara language lists for video language, languages to translate from and languages to translate into.
Three of them are (see also attachments):
What does it mean to translate existing subtitles into one of these three languages? And how can a video's language be one of them?