For teachers in schools with Family Portal available the visibility type on the assignment determines whether parents and students can see anything about the assignment.
To quickly change the type click on the icon in the column header in the scores side tab. You can also do this in the assignment side tab for a specific assignment in the field called Visibility Type.
Red no entry icon = Private (only teacher and staff with access to the gradebook can see)
Blue info icon = Public No Grades (details of assignment are available in portal)
Green Checkmark = Public (Student and Parents can see info and marks in portal)