A '<' Character Cannot Be Used In Attribute 'href', Except Through <[xml]

The following embedded snip it of PHP code won't validate using xhtml 1.0 strict. When validating I get the following error:

A '<' character cannot be used in attribute 'href', except through <[xml] Code:

href="/_Director/forms.php? <?PHP create_request_query('AskQuestions', 'AskQuestions'); ?>" Any idea what's wrong?