In the Twine SIS, the Dropped date is used to keep track of how long a student was enrolled in a class. In some cases, a student may enroll in a class but never attend, and you may want to completely delete the enrollment record. If the dropped date is earlier than the enrolled date, all record of the student's participation in the class will be permanently deleted from Twine. If the dropped date is equal to or after the enrolled date, Twine will retain the student’s start and end date in that class
