What do the blue or gray dots next to the teachers on the committee form mean?

If you select a committee, blue dots appear in front of the names of teachers whose presence is indispensable. To make a teacher non-indispensable, double-click on the dot and it will disappear.

If you conduct a multi-selection of committees, a blue dot indicates the teacher's indispensability in all the selected committees, while a gray dot indicates his/her indispensability in at least one of the selected committees.