Under German law copyright is non-transferrable. However, the copyright holder can grant another party unlimited usage rights as well as waive the right to be

Under German law copyright is non-transferrable. However, the copyright holder can grant another party unlimited usage rights as well as waive the right to be mentioned as the actual copyright holder. Both of these might apply here: SAP's and Deutsche Telekom's employees most likely have waived their right to be mentioned as individual copyright holders (which is a common stipulation in German employment contracts) while SAP and Deutsche Telekom have not, which is why they are mentioned as copyright holders instead of the Federal Republic of Germany.