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

contentRating

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

Thing > Property > contentRating

Official rating of a piece of content—for example,'MPAA PG-13'.

Usage: Between 1000 and 10,000 domains
Values expected to be one of these types
Text
Used on these types
CreativeWork

Schema Version 3.2