[dragonwriter]

> The client has not erred by requested a document that exists and which the server can technically provide

The client has erred in requesting a document which the server is legally forbidden to provide to that client. As specified for 403, the server understands the request and refuses to fulfill it.

Admittedly, a hypothetical 6xx Third-Party Interference series of error codes might be useful for these kind of cases (and some instances currently handled by 503.)

[nailer]

>> The client has erred

> The client has not erred... the server understands the request and refuses to fulfill it.

As I see it, the server is not refusing anything. +1 6xx Third-Party Interference.

Let's just agree to disagree.