A Course Reference Number (CRN) is a 5-digit number assigned to each UO course section for a term. While in a single term there may be multiple course sections offered for a particular course (i.e. AAD 250), a CRNs function is to serve as identification for a specific course section. To find the CRN for a particular course section, view the course details on the Schedule of Classes.
Each class offering of any course has its own unique identification number. This is referred to as the CRN (or Course Reference Number). Typically, the CRN consists of 5 digits for Spring or Fall semesters and 4 digits for summer semesters. For example, you might register for a fall section of an online Accounting 101 course which has a CRN of 20001.