diff --git a/tren.rst b/tren.rst
index d1aac90..9d8dffe 100644
--- a/tren.rst
+++ b/tren.rst
@@ -257,6 +257,26 @@
        embedded in filenames included this way are expanded as they
        would be from the command shell.
 
+       You can define an environment  variable, ``TRENINCL``, to specify
+       a path to search to find the named include file(s).  ``tren`` will
+       use the first (leftmost) instance of the include file it finds along
+       this path.  If none are found, ``tren`` uses the file path as passed on
+       the command line.  This allows relative- and absolute include
+       file paths to be used along with files in an include path::
+
+           export TRENINCL=$HOME/.tren:/some/where/else:/and/else/where
+           cp include_file $HOME/.tren/
+           tren.py -I include_file -I foo/rel_include -I /foo/bar/abs_include *
+
+           'include_file' will be found in $HOME/.tren/
+           'rel_include' will be found relative to current dir
+           'abs_include' will be found on absolute path
+
+       Note that when defining ``TRENINCL``, you must use the path
+       delimiter appropriate for the operating system in question.
+       For Windows, this is ``;``, For all other supported OSes, it
+       is ``:``.
+
   -i instances  Specifies which "instances" of matching strings should
                 be replaced.
                 (*Default*: 0 or leftmost)
@@ -2767,7 +2787,7 @@
 
 ::
 
-  $Id: tren.rst,v 1.184 2010/06/01 23:47:40 tundra Exp $
+  $Id: tren.rst,v 1.185 2010/08/27 17:11:35 tundra Exp $
 
 You can find the latest version of this program at: