preferredLanguages

Preferred languages, best first, as ISO 639 codes or BCP 47 tags.

A track matches when it names the same language in any spelling: ja matches a track tagged jpn or ja-JP, and de one tagged ger or deu. The first preference any track matches decides. Among its tracks, one whose script and region also agree comes first, so pt-BR prefers a pt-BR track and takes a pt-PT one over nothing.