That would be a layer/protocol violation. The HTTP status codes used in DoH are used to discuss the semantics of the DNS query itself, unrelated to the DNS resp

That would be a layer/protocol violation. The HTTP status codes used in DoH are used to discuss the semantics of the DNS query itself, unrelated to the DNS response. For example an NXDOMAIN response is still a 200, not a 404. Edit: for what it’s worth, Google is doing this the “right” way in the DNS protocol itself, see: https://news.ycombinator.com/item?id=40698650 https://news.ycombinator.com/item?id=40698650