The Subjects area allows the user to add additional subjects which feeds into the Classes or Simple Assessment module.
Go to Admin > Config > Core Set Up > Subjects.
Enter the subject name and abbreviation in the fields available, then click Add Subject.
You will now be able to assign these subjects in the Classes module or in Simple Assessments.
You are only able to delete a subject if no data has been entered against the subject. If it has not been used, there will be a delete button visible.