Cr/D/F is being phased out. Currently only the class of 2021 is elgible.
The Yale policy states the Cr/D/F option exists to “encourage academic experimentation and to promote diversity in students’ programs.” The DUS will determine eligibility by seeing if the proposed course is a diversity course relative to the other courses you’ve taken and relative to other S&DS majors. Please consult with the DUS if you want to use Cr/D/F for a course.
Cr/D/F is not allowed for the pre-requisite requirement.