It is good practice for MediaWiki extensions to support non-English namespace names (while having the English name as canonical name).
This doesn't appear to be the case at the moment, as "TimedText" and "TimedText_talk" are hard-coded inside TimedMediaHandler.hooks.php and there's no i18 file for the namespaces (if I understand correctly).
It should be possible for TimedMediaHandler to support namespace localization, not only for Wikimedia wikis but also for third parties. (For instance, the Portuguese Wikipedia community has requested that in bug 58984 comment 2.)
Version: master
Severity: normal
See Also:
https://bugzilla.wikimedia.org/show_bug.cgi?id=58984