[ssn] how to document ssn for FPWD

Hi Danh,
As you know, we did not get up to talking about how SSN should be documented for the FPWD in the SSN meeting last week. To push things along a little, could you kindly share what you are proposing for feedback  to the list? I am aware of time pressure and I would not like to delay this valuable work by waiting for another SSN-specific meeting.
--Kerry