Hi, I suggest you update http://www.w3schools.com/tags/tag_doctype.asp. The reason? The DTD isn't a tag, neither in HTML or XHTML. The W3C always calls it a doctype declaration/DTD, never a tag. I think it should stay in the taglist, but that it should be written on the page "The DTD is not a tag!", and the parts calling it a "tag" be reworded to call it a DTD or doctype declaration/definition, as said here and here.