Does this license have to be passed on (I don't have the technical term), if the licensed data is used or passed on?
Data licence Germany - Zero - Version 2.0
Any use is permitted without restrictions or conditions.
The data and meta-data provided may, for commercial and non-commercial use, in particular
be copied, printed, presented, altered, processed and transmitted to third parties;
be merged with own data and with the data of others and be combined to form new and independent datasets;
be integrated in internal and external business processes, products and applications in public and non-public electronic networks.
(Example data: search for zero-2-0 on http://www.geodatenkatalog.de)