Which statement correctly differentiates standard PGNs from proprietary PGNs?

• A. Standard PGNs are defined in the public catalog; proprietary PGNs are reserved for manufacturers and are not publicly documented.
• B. All PGNs are standard if they come from a gateway.
• C. Proprietary PGNs are always within 300-999.
• D. Standard PGNs are only used by talkers.

Answer: (A)

In NMEA 2000, data definitions are split into standard and proprietary messages. Standard PGNs are published in the public catalog, with their data fields, formats, and meanings defined so equipment from different manufacturers can interpret them consistently. Proprietary PGNs, on the other hand, are created by manufacturers for private use and are not publicly documented, often requiring a license or vendor documentation to read or implement. This distinction explains why standard PGNs enable broad interoperability, while proprietary PGNs are reserved for manufacturer-specific features. The other statements don’t fit because gateways don’t make PGNs standard by themselves, proprietary PGNs aren’t restricted to a fixed public numeric range, and standard PGNs aren’t limited to talkers only.