A registration for a student to write a Diploma Exam.
In PASI, this is a Diploma Exam Mark record:
If the Registration Deadline Date/Time is in the past, the Diploma Exam Mark record will no longer be considered a Diploma Exam Registration, regardless of the Exam Mark Status.
Generally, a registration is added before the Time. If a registration is submitted after the Exam's Time, it is referred to as a Diploma Exam Late Registration.
See Diploma Exam Process for more information on the diploma exam registration timelines.