If those rewriting rules have to be server-side, and I think that's what you mean, the answer to that is that browsers don't get to dictate terms to servers tha

If those rewriting rules have to be server-side, and I think that's what you mean, the answer to that is that browsers don't get to dictate terms to servers that way; browsers can say what they will and won't accept, especially in terms of content type, but URI format isn't generally something the browser can specify.