Possible digital content label rating tiers.

CONTENT_RATING_TIER_UNSPECIFIED Content label is not specified in this version. This enum is a place holder for a default value and does not represent a real content rating.
CONTENT_RATING_TIER_UNRATED Content that has not been labeled.
CONTENT_RATING_TIER_GENERAL Content suitable for general audiences.
CONTENT_RATING_TIER_PARENTAL_GUIDANCE Content suitable for most audiences with parental guidance.
CONTENT_RATING_TIER_TEENS Content suitable for teen and older audiences.
CONTENT_RATING_TIER_MATURE Content suitable only for mature audiences.