PUBLISH_NAMESPACE_CANCEL — MoQT draft-15 §9.22.

The subscriber sends an PUBLISH_NAMESPACE_CANCEL control message to indicate it will stop sending new subscriptions for tracks within the provided Track Namespace.

PUBLISH_NAMESPACE_CANCEL Message {
  Type (i) = 0xC,
  Length (16),
  Track Namespace (..),
  Error Code (i),
  Error Reason (Reason Phrase)
}

Figure 23: MOQT PUBLISH_NAMESPACE_CANCEL Message

Track Namespace: Identifies a track's namespace as defined in Section 2.4.1.
Error Code: Identifies an integer error code for canceling the publish. PUBLISH_NAMESPACE_CANCEL uses the same error codes as REQUEST_ERROR (Section 9.8) that responds to PUBLISH_NAMESPACE.
Error Reason: Provides the reason for publish cancelation. See Section 1.4.3.