Source : Free On-Line Dictionary of Computing

RTFM
     
         /R T F M/ Read The Fucking Manual (always
        abbreviated, sometimes bowdlerised to "Fine" or "Friendly") An
        (unhelpful) {guru}'s traditional response when someone asks a
        question in a {newsgroup} or {mailing list} which he could
        have easily answered for himself had he bothered to RTFM.
     
        The term may also be used to indicate that you couldn't find
        the answer in the manual.  E.g. "How do I interface Unix to my
        toaster?  And yes, I did RTFM but the {FM} didn't help and I
        can't {RTFS}."
     
        Other derived forms include {RTFAQ}, {RTFB}, {RTM}, and, more
        recently, {STFW}.  Compare: {UTSL}.
     
        [Earliest use?]
     
        [{Jargon File}]
     
        (2003-06-07)