Match Grades
Imported grades must match one of the
fixed list of valid grades, as follows...
  - 100%
- 90%
- 80%
- 75%
- 70%
- 66.666%
- 60%
- 50%
- 40%
- 33.333
- 30%
- 25%
- 20%
- 16.666%
- 14.2857
- 12.5%
- 11.111%
- 10%
- 5%
- 0%
negative values of the above list
are also permitted.
There are two settings for this switch. They affect how
the import routine treats values that do not exactly
match one of the values in the above list
  - Error if grade not listed
 If a question contains any grades not found in the list an error is displayed
  and that question will not be imported.
- Nearest grade if not listed
 If a grade is found that does not match a value in the list, the grade is changed
  to the closest matching value in the list
Note: some custom import formats write directly to the database and may bypass
this check