In an ambitious undertaking, a Joint Committee of two subspecialty societies concerned with pulmonary diseases (the American College of Chest Physicians and the American Thoracic Society) has attempted to standardize many of the terms and symbols currently used for pulmonary function and disease (1). Some of the Joint Committee's recommendations should be of interest to general physicians, as well as to subspecialists in pulmonary medicine and in respiratory physiology. The report updates previous recommendations of the "Pappenheimer Committee" (2) on symbols and provides definitions for certain terms used in respiratory physiology. The recommendations will hardly satisfy all authorities in the