It is the set of teaching units (or a single teaching unit) of a study programme that a student must have taken beforehand or at the same time as a specific course, that is to say during the same academic year. If a teaching unit is co-requisite, the student must simply register at the latest during the same academic year.

Example: The lectures "DROI-C2001 Constitutional Law: Institutions and Litigation" and "DROI - C2002 Rights and Freedoms" must be followed simultaneously in BA2