The ESCO occupations pillar is built on ISCO-08 which serves as the hierarchical structure for the occupations pillar. ISCO-08 provides the top four levels for the occupations pillar and ESCO occupations are located at level 5 and lower. In ESCO, each occupation is mapped to exactly one ISCO-08 code. Any occupation concept relevant to the European labor market is allocated within this hierarchy.
All occupation concepts contain one preferred term and any number of non-preferred terms and hidden terms in each of the 28 ESCO languages. ESCO as well provides an explanation (metadata) for each occupation profile such as description, scope note, reusability level and relationships between concepts. Furthermore, each occupational profile lists the knowledge, skills and competences that experts considered relevant terminology for this occupation on a European scale.