The normative policy document in section B.7 has two typos regarding the signing requirement for reference parameter 
headers: (1) the opening sp:Xpath element has an accidental forward slash and (2) there is a stray single-quote at the 
end of the XPath text:

(86)	          <sp:XPath/>
(87)	            /Envelope/Header/*[@isReferenceParameter="true"]'
(88)	          </sp:XPath>

should be changed to:

(86)	          <sp:XPath>
(87)	            /Envelope/Header/*[@isReferenceParameter="true"]
(88)	          </sp:XPath>