The blacklist is the list of students who cannot participate at the ITEC activities temporarily or permanently.
If you sign up for a course and you do not attend at least 25% of lessons, you will end up in the blacklist and won't be able to participate in other supplementary activities organized by the ITEC for 2 semesters: the current one, when included in the blacklist, and the subsequent one. In case you end up in the blacklist for a second time the exclusion from the activities becomes permanent.