I may be mistaken, but I don't think anybody uses exception inheritance at this point. If I'm correct, it should be removed from the spec.
I've only seen one bad instance of it. But I'm ok with not allowing it.
If nobody uses it, yes let's drop it. We can do that during CR, since I've noted that any features that don't gain adoption in specs will be dropped:
Marcos, what's the bad instance?
(In reply to comment #2)
> Marcos, what's the bad instance?
IIRC, one that was used by an older WAC spec (WACDeviceError or something, though it was probably wrong anyway). Those old specs have been taken offline.
I've explicitly listed it exception inheritance as "at risk".