Academic Settings / Marking Settings / General Settings / Assessments & Assignments / How to filter Students / A Students will be shown in the Assessments/exam marking form only if the Students is already registered as present in this assessment/exam
Setting->Active
If the setting is enabled and all students are absent, no students will appear in the marking form.
In order for a student to appear for grading he/she must first declare his/her presence
Setting -> Inactive
All absent students appear