Content Negotiation for XHTML Documents via PHP and htaccess

In this article, I discuss the different MIME types available for XHTML and explain a method for serving your documents with the optimal MIME type, depending on the capacity of the user agent. Using either htaccess or PHP for content negotiation, we can serve complete, standards-compliant markup for our document’s header information. This is especially helpful when dealing with Internet Explorer while serving a DOCTYPE of XHTML 1.1 along with the recommended XML declaration. According to the RFC standards 1 produced by IETF 2, web documents formatted as XHTML 3 may be served as any of the following three MIME types: Read more »