The US Selective Service recently mailed out 14,215 letters to men in Pennsylvania reminding them of their obligation to register for the draft. The agency is chalking up the blunder to an error with its computer systems that occurred during a routine automated data transfer between the State of Pennsylvania and Selective Service. Apparently the Selective Service uses just a two-digit code to identify someones birth year; Selective Service regrets any inconvenience caused the families of these men and assures them that the error has been corrected and no action is required on their part, the agency said in an urgent message on its website.