==== content_availability_descriptor

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

[source,xml]
----
<content_availability_descriptor
    copy_restriction_mode="bool, required"
    image_constraint_token="bool, required"
    retention_mode="bool, required"
    retention_state="uint3, required"
    encryption_mode="bool, required">

  <reserved_future_use>
    Hexadecimal content
  </reserved_future_use>

</content_availability_descriptor>
----
