The American Commission on Stratigraphic Nomenclature, recognizing the desirability of uniform usage in stratigraphic classification and terminology throughout the continent of North America, has proposed a new code of stratigraphic nomenclature. The prime purpose is 1) to formulate a usefully comprehensive, yet explicit statement of principles and practices for classifying and naming stratigraphic units, and 2) to secure the greatest possible uniformity in applying these principles and practices. This code is applicable to all kinds of rocks, sedimentary, igneous, and metamorphic. The Commission has been guided by the philosophy expressed in its reports on the nature, usage, and nomenclature of rock-stratigraphic, biostratigraphic, and time-stratigraphic units. The Articles of this code are recommendations that can not be generally mandatory, but geological organizations may adopt these articles as their rules of nomenclatorial procedure. This code provides regulations and recommendations relating to 1) rock-stratigraphic units, 2) stratigraphic units, 3) biostratigraphic units, and 4) time-stratigraphic units. The code also treats 2 categories of units that are not in themselves stratigraphic units but are closely related. These are 5) geologic-time units, which are fundamentally related in concept to time-stratigraphic units, and 6) geologic-climate units, which are based on Quaternary stratigraphic units.