Summary of Data Management Principles (DMP) prepared at the request of the DOE Office of High Energy Physics, in support of the DOE Office of Science Statement on Digital Data Management and for reference by those submitting proposals in response to DOE Office of Science Funding Opportunity Announcements. Submitted to DOE on July 2, 2015. This revised version 3.0 uploaded to docdb Mar. 9, 2017 and reflects the DES Public Data Release Plan finalized in Dec. 2016.