...OVERVIEW + Due to a retroactive change in German law introduced in January 2017, we believe that four systemically important German banks--Commerzbank AG, Deutsche Bank AG, Deutsche Pfandbriefbank AG (PBB), and UniCredit Bank AG--now have significantly improved additional loss-absorbing capacity (ALAC) buffers protecting senior creditors. + We've reviewed the documentation for each of these banks' long-term senior unsecured debt instruments that we rate, after placing our issue and issuer credit ratings on the banks on CreditWatch on Dec. 15, 2016. + We have also considered other important rating drivers, such as ongoing restructuring, any implications from possible increased economic risk in Germany, and group-related aspects. + As a result, we have raised by up to two notches or affirmed our long-term counterparty credit ratings on Commerzbank, Deutsche Bank, PBB, and UniCredit Bank, mainly reflecting stronger ALAC buffers, and removed the ratings from CreditWatch with positive implications....