If a device on the network uses a manufacturer proprietary PGN, how is this typically indicated?

• A. The PGN range or device documentation indicates proprietary; not publicly documented.
• B. It is reserved for standard catalogs.
• C. It uses a single-digit PGN.
• D. It always has a special label in the device.

Answer: (A)

Proprietary PGNs are identified by the fact that they fall outside the publicly published standard PGN catalog or are explicitly marked as proprietary in the manufacturer's documentation. In practice, if a device uses a PGN that isn’t documented in the public NMEA 2000 data dictionaries, you rely on the vendor’s own documentation to interpret the data fields. This is why the typical indication is either the PGN range used (distinct from standard ones) or a note in the device’s documentation stating that the PGN is proprietary and not publicly documented. The other ideas—such as a single-digit PGN or a universal special label on the device—don’t reliably signal proprietary PGNs, and standard PGNs are the ones that appear in the official catalogs.