The subtitle track containing forced and non-forced subtitles is associated with a subtitle track containing only forced subtitles.
- iOS 7.0+
- macOS 10.9+
- Mac Catalyst 13.0+
- tvOS 9.0+
- watchOS 2.0+
Non-forced subtitles usually transcribe all “normal” dialogue in a media asset and are typically not presented by default. Forced subtitles are those that are essential for presentation even when normal subtitles are disabled (for example, when a character speaks in a language foreign to that of the audio track).
Both subtitle tracks are expected to present forced subtitles with the same content and the same language, but may have different timing.