 This was attributed to a clerk at the Pennsylvania Department of Transportation who failed to select a century during a transfer of 400,000 records to the Selective Service; as a result, the system did not differentiate between men born in 1993 (who would need to register) and those born in 1893 (who would almost certainly be dead).This was compared to the "Year 2000 problem" ("Y2K bug"), in which computer programs that represented years using two digits instead of four digits were expected to have problems beginning in the year 2000.The Selective Service identified 27,218 records of men born in the 19th century made errantly applicable by the change of century and began sending out notices to them on June 30.