What are the chances of this being "accepted" and existing?
Also further to this how frequently are new HTTP Status Codes proposed like this and what percentage are/aren't "accepted"? Not sure if I should add it to http://httpstatus.es or not (with some sort of "proposed" signal)
451 implies an error on the client side, when the client has done nothing wrong. To an extent, neither has the server, so this probably better falls into the 300 category.
451 is OK for propaganda purposes, but will people outside of North America and the UK understand the context?
I don't think the protocol cares that much about who made the error. It's more about whether the client should retry the same unmodified request again or not. Using a 4xx series error code indicates that it shouldn't, using a 5xx series code indicates that it should.
Of course one can argue that censorship is only temporary and that actually it would make sense for clients to keep trying..
And yes people here in Finland understand the context.
Aside from the "statement" it makes, I think it is useful to identify responses that a resource provider might like to make but is not permitted to make (i.e. censorship).
Given the prevalence (editorial: "enormity") of censorship problems -- both current and pending -- being able to distinguish between them and other failures provides actionable information on a useful scale and frequency.
The particular response code proposed does make an elegantly concise and culturally cognizant statement -- something that RFC's are not entirely unknown for. The proposal is both practical and well-put, IMHO.
