What can be done for a field trip that involves only a few students in the class (in which case courses are maintained)?

Select all students who are going on an outing.

Right-click and select the Create a group.

In the pop-up window, enter a designation for the group. Keep the option Standard group and validate.

Go to the display Daily management and absences > Groups > Entry of absences. Students on a field trip will appear as such (on a pedagogical outing) in lists, roll call sheets, etc.