When a device uses standard or non proprietary connections, yet makes itself proprietary by only working with certain devices. A good example of this is Astro Mixamps and Astro A50 Base Stations. Sure they'll work on PS4, Xbox One, and PC, but the specific Mixamp or Base Station for each platform is needed.
Astro Headsets are semi proprietary
by Jayrod64* December 1, 2019