Symbols in the Gradebook

What do the symbols mean that I see in the Gradebook?

Gradebook displays student names, assignment scores, exemptions, and highlighted status indicators across four assessments.

This icon indicates that the student has accommodations.
This icon indicates that the student has an exception added for that assessment.
When a student is exempted from an assessment, the word Exempt is written in that column.
The purple dot indicates there is a new submission ready to be graded.

The red icon on the List View indicates that the due date of the assessment is past.
Gradebook lists two tutorials, showing submission counts, grades, deadlines, and grading status.