ISSUE-138 Downgrade strength of Issuer field's Organization attribute

http://www.w3.org/2006/WSC/drafts/rec/rewrite.html#signal-content

6.1.2 Identity Signal says for validated certificates: 

"The identity signal MUST include the Issuer field's Organization 
attribute to inform the user about the party responsible for that 
information."

I don't remember why that is for validated certificates. If we did this 
one to death already, please point me to it. Otherwise, my proposal for 
this issue is either:

A) Move that to AA certs only 
B) Change the MUST to a SHOULD. Which actually I feel is still too strong. 
But I'm guessing there's something I'm missing.