bularies must also include equivalent Activity Vocabulary
        properties and types as illustrated in Section C. Conforming documents
        must not use features of JSON-LD or other serialization features
        disallowed in this specification, as in Section 2. Conforming
        documents that include types or properties beyond those defined in the
        Activity Streams 2.0 Vocabulary must use the extensibility features
        defined in section 5.
      </p>

      <p>
        A non-exhaustive 