The Oncology Nutrition Dietetic Practice Group has worked together with the Commission on Dietetic Registration to create a Board Certification for Registered Dietitians in Oncology Nutrition. The first exam was given in 2008. CSO is the credential abbreviation for Board Certified Specialist in Oncology Nutrition. A minimum of two years of clinical practice with documentation of 2,000 hours of practice experience in the oncology care setting is required. For more information, please consult the Commission on Dietetic Registration.