==== node_relation_descriptor

Defined by ARIB in <<ARIB-B10J>>.

[source,xml]
----
<node_relation_descriptor
    reference_type="uint4, default=0"
    information_provider_id="uint16, optional"
    event_relation_id="uint16, optional"
    reference_node_id="uint16, required"
    reference_number="uint8, required"/>
----
