Author(s) and publish date By: Ted Guild Published: 8 February 2008 Skip to 105 comments If you view the source code of a typical web page, you are likely to see something like this near the top: <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> and/or <html xmlns="http://www.w3.org/1999/xhtml" ...> These refer to HTML DTDs and namespace