What Do the Letters After Course Numbers Mean?

You've likely noticed that many courses end with a letter. Maybe you have heard of (or taken) CS106A or English 9CE. But what do those letters mean?
The short answer is that it varies. Different departments use these letter to signify different things.
There are a few standard guidelines that you will see across many departments:
N— frosh IntroSem
Q— sophomore IntroSem
SC— sophomore college
AX — arts intensive
SI— student-initiated
The use of other letters depends on the department. Be sure to read the full course description in ExploreCourses for guidance, and click the blue Schedule link to see if there is more information in the Notes. Here are some common approaches (note that "A" is used differently in each one):

  • Letters frequently signal that courses are a variation on the same basic content, such as with Engr40, Engr40A, Engr40M; HumBio120 or HumBio120A; Math61CM or Math61DM.
  • A-B-C will sometimes refer to a sequence of courses, but not always--you can usually tell from the course descriptions and prerequisites.
  • A may also be used to denote a 1-unit auxiliary course or a course with an additional auxiliary component, such as CS103A or Math51A, although there are many different ways auxiliary courses are presented.
  • An A in a PWR course might even stand in for the instructor's initials.
See if the courses in your department show a pattern, or consult the department SSO, your Academic Advising Director, AARC Advisor, or your Major Advisor.