d by that original specification remains intact. Specific
      processing rules are defined by
      this specification that allow existing Activity Streams 1.0
      documents to be mapped to and processed as an Activity Streams 2.0
      document.
    </p>

    <p>
      The JSON syntax defined by this specification differs somewhat from
      that defined in the original JSON Activity Streams 1.0
      [[AS1]] specification in ways that are not backwards
      compatible.  Implementations can choose to 