core + attic (Attic Area): these terms have been either deprecated from the core or extentions, or removed from pending as not accepted into the full vocabulary.

subtitleLanguage

Canonical URL: http://schema.org/subtitleLanguage

Thing > Property > subtitleLanguage

Languages in which subtitles/captions are available, in IETF BCP 47 standard format.
Values expected to be one of these types
Language
Text
Used on these types
Movie
ScreeningEvent
TVEpisode

Schema Version 3.3