The CNO-11 is covered in the conceptual framework of ISCO-08. The classification criteria used are the type of work carried out and skills. Skills are taken to mean the ability to perform tasks that are inherent to a specific job, for which two points of view are taken on board: the level and specialisation of the skills.
The CNO-11 is more broken down than the ISCO-08. It presents an intermediate level between the first and second levels of the latter, which smoothes the structure and which should be regarded as an alternative to the Large Groups.
The objective is to guarantee uniform handling of statistical data regarding occupations on a national level and their international and community comparability.