I coined it initially for configuration management, but... "Keep accidental an intentional identity apart". By that I try to convey that just because two thing

I coined it initially for configuration management, but... "Keep accidental an intentional identity apart". By that I try to convey that just because two things look the same doesn't mean that they are by necessity the same. So if it is a case of "happens to look the same", keep things separate, but if they're fundamentally linked, keep only one copy and reference it. In terms of code, I think that means "repeat the codepath if the two copies just happen to look the same today, but are not necessarily going to do so in the future" and "if the code paths are always going to be identical, make a function/procedure". That can probably e extended to subclassing as well.