Yes, but GET, HEAD, PUT, and DELETE do very different things. You can write an idempotent PATCH mechanism. If that's what you want, you can do it. You control

Yes, but GET, HEAD, PUT, and DELETE do very different things. You can write an idempotent PATCH mechanism. If that's what you want, you can do it. You control the server, so you can restrict the accepted patch formats to idempotent ones. Adding an HTTP verb doesn't make patching magically happen. Someone has to write the logic, either you or your framework authors. Obviously there will be different mechanisms and some will be effectively idempotent. Again, not in the mathematical or functional programming sense, but in the colloquial DBA sense, at least. Limiting HTTP PATCH at the protocol level would be a huge mistake, I think. None of this should be construed to mean that I see a clear need for a new HTTP verb, though.