RTM /R-T-M/ [USENET abbreviation for `Read The Manual'] 1. Politer variant of RTFM. 2. Robert T. Morris Jr., perpetrator of the great Internet worm of 1988 (see {Great Worm,the} ); villain to many, naive hacker gone wrong to a few. Morris claimed that the worm that brought the Internet to its knees was a benign experiment that got out of control as the result of a coding error. After the storm of negative publicity that followed this blunder, Morris's username on ITS was hacked from RTM to RTFM.