Does code require that you use only breaker brands explicitly listed on the breaker box, or are "compatible" breakers compliant?
At least in the US, The governing authority on this matter is the Nationally Recognized Testing Laboratories (NRTLs), such as UL.  The breaker panel itself is UL Listed to work with the breakers on its label.  However, other brands can make compatible breakers and submit them to UL testing to ensure they work safely, and then these breakers become UL Classified for use with that panel, and are legal to use.  Eaton's CL (CLassified) line is one example of this -- Eaton formally stating they're compatible means nothing, what matters is that UL stated that they're compatible based on their independent testing.