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.