I think, this is a general design feature. The specs explicitly allow a possible document body. If the status doesn't affect the process of retrieving the reque

I think, this is a general design feature. The specs explicitly allow a possible document body. If the status doesn't affect the process of retrieving the requested document (like a redirect), a client is free and even expected to display the document body. Having said that, if the status code is in the 4xx client error range, I'd wish that any document.title would be strictly ignored and browsers would always display the status code (together with the human readable error title) as the page title.