The Selected Characteristics of Occupations (SCO) is a companion volume to the U.S. Department of Labor's Dictionary of Occupational Titles, Revised Fourth Edition, published in 1991. These volumes were intended to provide a detailed representation of thousands of individual occupations in the United States, for the purpose of occupational information, occupational exploration, and job placement. The Social Security Administration was particularly interested in the Dictionary of Occupational Titles and the SCO for the purpose of establishing the existence of jobs that a claimant for disability benefits could otherwise perform despite his or her mental and/or physical impairments during disability adjudication within the Social Security Administration. The Dictionary of Occupational Titles was insufficient for disability adjudication at the Social Security Administration because it did not include enough detail about the physical and environmental demands of the jobs listed therein. Accordingly, the Social Security Administration requested that the Department of Labor produce a companion volume to the DOT, which would publish data collected as part of the DOT research, but not previously available. This document is known as the "SCO" or Selected Characteristics of Occupations Defined in the Revised Dictionary of Occupational Titles. The Social Security Administration's Interest in the SCO In 1960, Kerner v. Flemming, 283 F.2d 916, 921 (2d Cir. 1960) held that there must be a "rational decision" regarding the vocational issues. In response to Kerner and the underling demand for rationality inherent in District Court review, the SSA undertook a search for vocational evidence to support its disability determinations. Prior to the publication of the Fourth Edition of the DOT, the Social Security Administration requested estimates of worker traits from the Bureau of Employment Security. "There was also widespread interest among vocational consultants in an abstract of worker traits and physical requirements for occupations such as the Estimates of Worker Trait Requirements for 4,000 jobs, which had been published with the second edition of the Dictionary of Occupational Titles. Basic information about the physical capacities, working conditions, general educational development and specific vocational preparation requirements for the individual jobs could be ascertained by referral to this work. However, such information was needed in more accessible form for vocational assessment, therefore, the Bureau of Disability Insurance entered into an arrangement whereby the Bureau of Employment Security compiled and published a Supplement to the Dictionary of Occupational Titles. Microfilmed data about occupations furnished by the Labor Department was punched into