XHTML 1.0 2e -- scripts and validity?

I noticed there is no mention of a script not violating the validity of an XHTML 1.0 document.  The HTML 4 Recommendation included a provision which neither XHTML 1.0 nor XHTML 1.1 requires of scripts; the provision was that a conforming XHTML 1.0 document could not be broken by a script.