Is the valid DTD elements listed by w3schools for the XHTML 1.1 correct?

[kshin98]

According to the "HTML Elements and Valid Doctypes" page at "http://www.w3schools...ef_html_dtd.asp", the tags like 'thead', 'tbody', 'col', 'del', 'ins' are invalid for XHTML 1.1. But when I checked with the official DTD at "http://www.w3.org/TR...DTD/xhtml11.dtd", they all look properly included and valid elements for the xhtml1.1. I know that there are two versions of table modules supported by XHTML1.1 specification: one with 'thead', 'tbody', 'col' and another one without them(whick is called "Basic Table Module" if anyone cares). But I think the official DTD uses the one with those tags, not the one without them. The edit module which includes 'del' and 'ins' elements seems to be include at the official DTD as well. (I think there are several more tags with the mis-matching validity like above, but I am too lazy to list them all) It's very confusing