You can specify trn environment variables in an initialization file with all
the options.  See the first hint for details on that.  Certain environment
variables, like RNINIT, must be set in your shell (how else does trn know
to look there for the rest?).  Others, like REPLYTO may be useful in other
programs, so you could consider putting that in your shell startup file too.
But most of them are specific, like MAILHEADER, so you might as well set them
in the init file with the -E option.  That's why most of them look like
-EMAILHEADER=xx rather than MAILHEADER=xx -- to remind you.

Helpful hints:

 +  Two  useful flags are the -p and -G flags.  -p means to automatically
    select any thread that you have posted a message to.  This makes it very
    easy to track replies to your insightful comments :-) (to automatically
    select other threads, try the 'T' command).  -G tells the 'g' command
    to use a loose match algorithm on groups it can't find.  So if you type
    "g news.softwre.raeders.genrl", it will assume that you meant to type
    news.software.readers and take you there.  It is usually easier to type
    "/reader" than using a 'g' command, but use -G too.

 +  The 'X' command in the selector (kinda like catchup/yes) can be made the
    default action on the last page of selections by using the command-line
    option:  -XX.  This lets you browse all the pages, making selections as
    you go, and then mark everything that was not selected as read when you
    press space at the last page.

 +  If you like to select a little, read a little, and then select a little
    more, try using the command-line option:  -XDD.  This makes the 'D'
    command the default on all pages of the selector.  Thus you can select
    the things you want to read on the current page, press space, and you
    will read the selected articles immediately (if there were any).  All
    other articles on the current page will be marked as read.

 +  To use mush to send all R)eplies, put this in your .trn/trnrc file:
	[environment]
	MAILPOSTER="mush -h %h"

 +  To use elm to send all R)eplies:
	[environment]
	MAILHEADER="\\000"
	MAILPOSTER="elm -i %h -s '%'s' %t"

 +  To tailor the time field:
	A good example is LOCALTIMEFMT="%A, %B %e %Y, %r %Z" which becomes:
	Date: Saturday, June 12 1993, 08:15:32 PM PDT.  (The default is
	"%a %b %e %X %Z %Y", which is like the date(1) command).  See the
	strftime(3C) man page for more details on other % characters.

 +  To tailor the "In article <blahblahblah>, joe@user (Joe User)" line:
	person's name only: %)f
	person's address only: %>f
	For example: ATTRIBUTION='According to %)f <%>f>:'

 +  A better kill file scheme than the default (which creates obtuse
    directories all over your ~/News directory) is to use the following:
	KILLGLOBAL="%p/Kill/Global"
	KILLLOCAL="%p/Kill/%C"
    Where %p is your news directory, usually ~/News, and %C is the full name
    of the group, like sci.bio.  This means the kill file for sci.bio is in
    ~/News/Kill/sci.bio instead of ~/News/sci/bio/KILL.  Think about this
    next time you subscribe to alt.swedish.chef.bork.bork.bork :-)

    Note that you need a file system that allows long file names to make
    this work.

 +  If you're tired of endless subscription notices to newsgroups you could
    care less about, look at the AUTOUNSUBSCRIBE variable.  There's a
    companion AUTOSUBSCRIBE function too.  For example, to automatically
    unsubscribe all NEW alt groups, use ^alt.*.  More dramatic, to
    unsubscribe to everything BUT certain groups, use "*,!^local.*,!^comp.*",
    for example.  If you're REALLY tired of them, use -q to tell trn to not
    even check for new groups at all.

 +  If you want replies to your postings to go to a machine other than the
    machine you're posting from, set the REPLYTO environment variable.  For
    example, you might set this if you were trn's author:
	REPLYTO="wayne@clari.net (Wayne Davison)"

 +  You might like to redefine the 'u' keys in the following way:  'u' visits
    the "Set unread?" prompt (except in the thread selector), 'U' goes
    directly to the already-read article selector, and Ctrl-U unsubscribes
    from the group (even while in the thread selector).  Put the following
    3 macros in your .trn/macros file to accomplish this:

	u	%(%g=r?U:u)
	U	%(%g=r?U+:U)
	^U	%(%g=s?+u:u)

 +  If you like to be able to move forward/backward by article number more
    often than you need to search by subject, redefine ^N and ^P to be _N
    and _P by putting these lines into your macro file:

	^P	%(%m=[aep]?_P:^P)
	^N	%(%m=[aep]?_N:^N)

 +  If you like the way that 'q' worked in the thread selector in trn 1.x,
    put the following macro in your macro file:

	q	%(%g=s?+:q)

 +  If you would like the 'f' command to always answer yes to the "Are you
    starting an unreleated topic?" question, put this line into your macro
    file:

	f	%(%m=[ap]?fy^m:f)

 +  If you want to be able to save your shar headers in a file as they are
    extracted and you have access to "unshar" (a program that can extract
    shar files while saving the headers in UNSHAR.HDR), twiddle the external
    extract command to send the entire article:

	EXSAVER="%e <%A"

    and then point the UNSHAR variable at unshar instead of /bin/sh:

	UNSHAR="unshar -s"

    Note that this assumes that any other commands you execute with
    "e dir|command" can also handle the entire article as input
    (uuencoded and shipped files are not affected).

 +  The following lines represent trn's default headers for posting an
    article.  If you want to customize your header copy this to your
    .trn/trnrc file and modify it (and _don't_ use Pnews directly to post,
    use trn -- the ":post" command from newsgroup's selector works well
    for this).

[environment]
NEWSHEADER='\
%(%[followup-to]=^$?:%(%[followup-to]=^%n$?:X-ORIGINAL-NEWSGROUPS: %n
))Newsgroups: %(%F=^$?%C:%F)
Subject: %(%S=^$?%"^J^JSubject: ":Re: %S)
Summary: 
Expires: 
%(%R=^$?:References: %R
)Sender: 
Followup-To: 
%(%{REPLYTO}=^$?:Reply-To: %{REPLYTO}
)Distribution: %(%i=^$?%"Distribution: ":%D)
Organization: %o
Keywords: %[keywords]
Cc: %(%F=poster?%t:%(%F!=@?:%F))
^J'

At one point in life, trn's author had the following .trninit file:
----------------------------------------------------------------------
-+ -XX -B -N -f -x11ms "-F> " -pp -G -u -mu -a
-hunrecognized
-ELOCALTIMEFMT="%A, %B %e %Y, %r %Z"
-ESELECTCHARS="abdefgijlmorstuvwxyz1234567890BCFGHIKVW"
-EKILLLOCAL="%p/Kill/%C"
-EKILLGLOBAL="%p/Kill/Global"
-EMAILPOSTER="elm -i %h -s '%'s' %t"
-EFORWARDPOSTER="elm -i %h -s '%'[subject]' %\"^J^JTo: \""
-EFORWARDHEADER='^J'
-EATTRIBUTION="According to %)f <%>f>:"
----------------------------------------------------------------------

and the following .trn/macros file:
----------------------------------------------------------------------
;	%(%m=p?|less^J:;)
u	%(%g=r?U:u)
U	%(%g=r?U+:U)
^U	%(%g=s?+u:u)
~T	s ~/Mail/trn
~M	| /bin/mail davison
^[^[	^[
----------------------------------------------------------------------