ARF-ARF is a virus on IBM's PC-DOS. It was downloaded from BBS sites and claimed to “Sort” the DOS Diskette Directory. This was a very desirable feature because PC-DOS didn’t list the files in alphabetical order in 1983. Instead, the program deleted all of the files on the diskette, cleared the screen and typed ARF – ARF. ARF was a reference to the common “Abort, Retry Fail” message you would get when a PC could not boot from a diskette.