Structured values are used when the value of a property has a more complex structure than simply being a textual value or a reference to another thing.
Represents additional information about a relationship or property. For example a Role can be used to say that a 'member' role linking some SportsTeam to a player occurred during a particular time period. Or that a Person's 'actor' role in a Movie was for some particular characterName. Such properties can be attached to a Role entity, which is then associated with the main entities using ordinary properties like 'member' or 'actor'.
See also [blog post](https://blog.schema.org/2014/06/16/introducing-role/).
A named tag on a Thing. about → the tagged resource; object → optional more specific referent (e.g. a snapshot Action). Does not copy or materialise the resource state.