on w3schools.com i was reading a tutorial on xhtml. there, it states some attribues not valid in base, head, html, meta, param, script, style, and title elements - especially the id attribute. i then was looking at w3.org. i came across the following in chapter 'C.14. Referencing Style Elements when serving as XML'"In HTML 4 and XHTML, the style element can be used to define document-internal style rules. In XML, an XML stylesheet declaration is used to define style rules. In order to be compatible with this convention, style elements should have their fragment identifier set using the id attribute, and an XML stylesheet declaration should reference this fragment"misleading tutorial ??? help