Identifies the canonicalization method applied to the data to be signed.
Select http://www.w3.org/TR/2001/REC-xml-c14n-20010315 or http://www.w3.org/TR/2001/REC-xml-c14n-20010315#WithComments; not required.
http://www.w3.org/TR/2001/REC-xml-c14n-20010315