The Road to XHTML 2.0: MIME Types

Here's a dirty little secret: browsers aren't actually treating your XHTML as XML. Your validated, correctly DOCTYPE'd, completely standards compliant XHTML markup is being treated as if it were still HTML with a few weird slashes in places they don't belong (like
and ). Why? The answer is MIME types.

Pilgrim, Mark. XML.com (2003). Articles>Web Design>XHTML>Standards

Recommended List of DTDs You Can Use in Your Web Document

When authoring document is HTML or XHTML, it is important to Add a Doctype declaration. The declaration must be exact (both in spelling and in case) to have the desired effect, which makes it sometimes difficult. To ease the work, below is a list of recommended declarations that you can use in your Web documents.

W3C (2007). Articles>Web Design>Standards>XHTML

XHTML Cheat Sheet  

This XHTML cheat sheet is excellent for XHTML coders. Along with many basic attributes, this two-page grid includes references that even experienced web professionals would find useful. Three types of elements are defined in this cheat sheet: block, inline and table elements. The miscellaneous section includes 22 additional elements. Each row contains the name, description and attributes of each of the elements available for use.

Flyspray (2007). Resources>Web Design>Standards>XHTML