The commentary offers a unique specialized commentary in the market that provides guidance on the handling of the Mortgage Bond Act. Special attention has been paid to addressing as many known and practically relevant issues related to the Mortgage Bond Act as possible and to offering appropriate solutions. The appendix contains the texts of the Present Value Regulation, the three Valuation Regulations (Mortgages, Aircraft, Ships), and the Coverage Register Regulation. Thus, the work is an indispensable and comprehensive tool for all questions regarding mortgage bond law. Rainer Smola served for many years as in-house counsel in the legal departments of BHW Bausparkasse AG and Deutsche Postbank AG. In both roles, he was intensively involved in the refinancing of these credit institutions, particularly concerning the special statutory regulations of the Building Society Act at BHW Bausparkasse AG.