From the usenet jargon file (hacker dictionary):

:RTFM: /R-T-F-M/ [UNIX] imp. Acronym for `Read The Fucking
   Manual'.  1. Used by {guru}s to brush off questions they
   consider trivial or annoying.  Compare {Don't do that, then!}
   2. Used when reporting a problem to indicate that you aren't just
   asking out of {randomness}.  "No, I can't figure out how to
   interface UNIX to my toaster, and yes, I have RTFM."  Unlike
   sense 1, this use is considered polite.  See also {FM},
   {RTFAQ}, {RTFB}, {RTFS}, {RTM}, all of which mutated
   from RTFM, and compare {UTSL}.

There is a anonymous ftp-server to provide the FAQ lists of all
usenet newsgroups. To get a FAQ list, type the following:
  > ftp rtfm.mit.edu      /* connect to the site; a message follows */
  > anonymous             /* type this when it asks for your name */
  > <your email address>  /* type your address as the password */
  > cd /pub/usenet        /* go to the directory you want to be */
  > cd <newsgroup name>   /* one level down (no slash).  */
  > dir                   /* look at what's there */
  > get <abbrev>_F_A_Q    /* get the file; case-sensitive */
  > quit                  /* stop this mysterious thing */
The parts in angle brackets are provided by you! <abbrev> is usually
the first letters of the newsgroup name separated by dots, for example:
  > Newsgroup: alt.emulators.ibmpc.apple2
  > Abbrevation: a.e.i.a
  > Filename (usually): a.e.i.a_F_A_Q
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ObJoke: And yes, it was in TFM, I just never R! :-)
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