An exclusion is a set of two or more courses where both may not count towards the requirements of your degree. Students are not normally permitted to register in a course that excludes one that they currently hold, so this warning should not occur that often. However, under certain circumstances departments may authorize an over-ride of an exclusion and allow the student to register, on the understanding that both courses are not allowed to count. This can occur in cases where the student has changed Plans and needs the excluded course as a prerequisite.
If an exclusion warning appears, first check the course(s) that are excluded. Usually, the exclusion appears as “No more than 3.0 [or 6.0] units from [List of courses]”. The extra courses are still being counted in the Program unit count extra electives must be taken to make up the deficiency. If both excluded courses also appear in the Plan requirements, you will have to use other courses to meet that requirement.