OBTS 1981 data were collected by California, Ohio, Pennsylvania, Utah, Minnesota, New York, and Virginia from existing data. The data set includes reported felony cases disposed during calendar 1981. The OBTS record reflects an arrest-to-disposition event that is a composite of the most serious charge, disposition, and most serious sentence. The 1981 OBTS of the seven States are available in the formats of card image and OSIRIS. The codebook information presented in this manual consists of one example of information appearing in the machine-readable codebook for a typical variable. The example is explained in detail. The variable description list presents the variables under the general classifications of processing, offender characteristics, entry into the system, prosecutor or grand jury, court disposition, and sentencing. Appendixes contain numerical codes for substantive offenses under uniform offense classifications as well as State/county arresting agency codes. Glossary and frequency tables.