WML document DTD, header, and validation

Opera 8.5 thinks totally unobjectionable the URL

 > http://tlvp.home.att.net/wap.wml ,

but your Validator complains as follows:

 > Sorry! This document can not be checked.
 >
 > Sorry, I am unable to validate this document because its content type is text/wml,
 > which is not currently supported by this service.

Does the W3 Validator still not do text/wml (or text/vnd.wap.wml) validation at all?
Or is this happening because the "top matter" in the file is "wrong"? That's:

<?xml version="1.0" encoding="utf-8" ?>
<!DOCTYPE wml PUBLIC "-//WAPFORUM//DTD WML 1.1//EN" "http://www.wapforum.org/DTD/wml_1.1.xml">

If this is the problem, what might more appropriate "top matter" be?

Thank you! -- Fred Linton

NOTE: If possible, please Cc: to this address any followup made to the list. Thx.