The author provides a comprehensive overview of the applicability of the abstract debt promise in credit security with this book. She primarily examines the permissibility of the abstract debt promise in general terms and conditions. In doing so, she extensively addresses the assumption of personal liability in the context of the establishment of a mortgage, which is commonly classified as an abstract debt promise. Finally, the security options of the abstract debt promise in connection with the real accessory security rights are explored. In particular, the possibilities of pledging business shares within the framework of credit syndication are investigated.