The request couldn't be processed due to semantic errors... perhaps such as not being mapped to a handler :->
I suppose from the right point of view that could also be likened to a reverse proxy not being able to send the request on (502 bad gateway), but sane people would probably find that even more confusing.
There were also attempts to use 204 no content for "I successfully confirmed that what you asked for doesn't exist", but I think I managed to shoot those down.
The request couldn't be processed due to semantic errors... perhaps such as not being mapped to a handler :->
I suppose from the right point of view that could also be likened to a reverse proxy not being able to send the request on (502 bad gateway), but sane people would probably find that even more confusing.
There were also attempts to use 204 no content for "I successfully confirmed that what you asked for doesn't exist", but I think I managed to shoot those down.