Although this is outdated, it was formerly part of the education system according to the General Law on Education and Funding of the Education Reform, of 4 August 1970.
Students who had completed the EGB and did not pursue Upper Secondary Education or the REM could take 1st grade Vocational Training. Students who either attained a certificate in Upper Secondary Education, completed the first stage of REM or the 1st grade Vocational Training could pursue 2nd grade Vocational Training.
Students who completed 2nd grade Vocational Training and decided to continue advanced studies in the same specialisation were granted direct entry into the relevant University Schools. To get into the Faculties or the Advanced Schools, students had to complete the COU.