Vendor ID and device ID together indicate a specific device. If you make a physically and electrically compatible device, it would make sense to also indicate t

Vendor ID and device ID together indicate a specific device. If you make a physically and electrically compatible device, it would make sense to also indicate that fact by duplicating the vendor and device IDs. There's no 'legality' involved in duplicating device codes. "Imitation is the sincerest form of flattery.". The practice is widespread of using the same code numbers for interchangeable devices by differing manufacturers: batteries (AAA, AA, 2025, etc), thermionic valves/tubes (6A7, 12AG8, etc), ICs (555, Z80, 8085, etc), and so on and so forth.