Classification schemes such as the International Standard Classification of Education (ISCED) play a key role in the understanding and ‘value’ of qualifications and professional activities: Although initially developed only for statistical purposes, they also have an impact on e.g. application and recruitment processes, remuneration and access rights. The assessment criteria that are subject to the schemes are not always obvious, especially since the schemes often refer to each other. Against this background, the aim of the contribution is to examine the role of classification schemes in attributing and classifying the value of (professional) education and qualifications. To this end, four classification schemas are examined for their comparisons of qualifications and professional activities and their contexts of development, and critically question the particular role of ISCED in this context.