The forum software is asking me
Oh yes, I’m absolutely positive that I want to revive this topic. The language-based redirect works if only one language is present in the Accept-Language header and only if no quality value is given. This feature is useless in its current form and only causes confusion. Even a vanilla installation of Chrome sends a header that cannot be interpreted by your redirect engine: en-US,en;q=0.9. I think you should either complete this feature or admit that you’re not going to implement it and simply remove it from the documentation.