Illustration of the classification process for the cluster classes introduced in Sect. 3.2.2. We abbreviated the counterpart associated via NWAY to CTP for better readability. The decision points are described in detail in Sect. 3.2.1. The numbers in parentheses denote the number of candidates. About one third of the clusters belong to Class 2, where an AGN is located in projection to the cluster. The clusters hosting bright AGN are categorized in Class 3. Misclassified clusters without apparent AGN contribution (Class 4 and Class 5) comprise about one half of the sample, and Galactic contaminants (Class 1) and those sources without counterpart information (Class 0) contribute only a small part.