The unique identity of the value in the domain. This is only used if the value is mutable; in practice this applies only to shared data types.
Used to specify the language for a particular string value or the default language of a JSON-LD document.
Used to set the data type of the typed value.
Used to specify the data that is associated with a particular property in the graph. Note that:
@valuewill never be a Variable.
@valueto be any JSON-serialisable type, to allow for custom datatypes. If a value that is not a string, number or boolean is used and there is no corresponding custom datatype, a TypeError may be thrown.