Really minor thingy, the element declaration of xsl:param has:

<xs:assert
    test="if (normalize-space(@static) = 'yes') 
          then normalize-space(@visibility) = ('', 'private', 'final') 
          else true()">
    <xs:annotation>
        <xs:documentation>
            <p>When the static attribute is present with the value yes, 
               the visibility attribute must not have a value other 
               than private or final.</p>
        </xs:documentation>
    </xs:annotation>
</xs:assert>

which I believe is redundant: there is no visibility attribute anymore.