es that
      are not recognized by other implementations. Care should be taken to not
      unduly overlap with or duplicate the existing Object types.
    </p>
    <p>
      When an implementation uses an extension type that overlaps with a core
      vocabulary type, the implementation MUST also specify the core vocabulary
      type. For instance, some vocabularies (e.g. The Good Relations
      Vocabulary) define their own types for describing locations. An
      implementation that wishes, for example