Latest version has been included in KeyConceptsDeliberation-WorkingDraft-7March2017.pdf, Section 2.3, as work on this overall Statement of Purpose continues as part of deliberation.
See also Phase 1 documents (https://community.icann.org/x/p4xlAw) for poll questions and responses that pertain to this draft Statement of Purpose.
Prior to continuing deliberation, the last stand-alone Statement of Purpose document was:
Clean: DraftRDSStatementofPurposev10-Clean.docx
Markup: DraftRDSStatementofPurposev10-Comments-upd25 October 2016.docx
