Like the previous volumes, the Documentary Yearbook 1991 focuses on the United Nations' family of international organizations and on several non-UN intergovernmental organizations of developing states. The most important documents which were issued in the course of 1991 are reproduced (in whole or in part), while other relevant documents are listed.

Already in its 6th year of existence, this Documentary Yearbook provides an independent collection of documents related to ocean affairs and the law of the sea, issued each year by international organizations. The Yearbook is arranged systematically and thereby gives the community of scholars and practitioners in ocean affairs and the law of the sea much improved access to essential documentation.