 JSON document whose root value is an
        Activity Streams <a>Object</a> of any type, including a
        <a>Collection</a>, and whose MIME media type is
        "<code>application/activity+json</code>".
      </p>

      <p>
        Activity Streams 2.0 documents MUST be serialized using the UTF-8
        character encoding.
      </p>

      <section id="jsonld">
        <h3>JSON-LD</h3>

        <p>
          The serialized JSON form of an Activity Streams 2.0 document MUST
          be consistent wi