-``Address.Topic`` and ``ParseTopic`` cover device descriptor,
-availability, reported values, telemetry, events, commands, command
-batches, results, and Zigbee hub status. Subscription helpers supply the
-core input filters, each device's command filter, and hub status filter.
-The command filter includes the reserved ``$batch`` target.
-
-``EncodeEnvelope`` and ``ParseEnvelope`` validate schema, IDs, optional
-UTC timestamps, and a required object payload. Unknown envelope fields,
-trailing JSON, unsupported schema versions, and malformed topics are
-errors. A receiver checks expiry against its own clock. The message ID
-stays unchanged on retry. Its timestamp is not the observation time.
+Private topic helpers cover device descriptor, availability, reported
+values, telemetry, events, commands, command batches, results, and
+Zigbee hub status. Subscription helpers supply the core input filters,
+each device's command filter, and hub status filter. The command filter
+includes the reserved ``$batch`` target.
+
+Private envelope helpers validate schema, IDs, optional UTC timestamps,
+and a required object payload. Unknown envelope fields, trailing JSON,
+unsupported schema versions, and malformed topics are errors. A receiver
+checks expiry against its own clock. The message ID stays unchanged on
+retry. Its timestamp is not the observation time.