What contextid does this letter apply to (for now these will always be courses, but later…)
lowerboundary
DECIMAL
10,5
null
The lower boundary of the letter. Its upper boundary is the lower boundary of the next highest letter, unless there is none above, in which case it’s grademax for that grade_item.
letter
VARCHAR
255
The display value of the letter. Can be any character or string of characters (OK, A, 10% etc..)