diff --git a/README b/README
index e4fc948..56fbfc3 100644
--- a/README
+++ b/README
@@ -1,4 +1,4 @@
-Z(1)                             User Commands                            Z(1)
+Z(1)				  User Commands				     Z(1)
 
 
 
@@ -17,8 +17,8 @@ AVAILABILITY
 DESCRIPTION
        Tracks your most used directories, based on 'frecency'.
 
-       After  a  short  learning  phase, z will take you to the most 'frecent'
-       directory that matches ALL of the regexes given on the command line.
+       After a short learning phase, z will take you to the most 'frecent' direc‐
+       tory that matches ALL of the regexes given on the command line.
 
 
 OPTIONS
@@ -29,39 +29,49 @@ OPTIONS
 
 
 EXAMPLES
-       z foo     cd to most frecent dir matching foo
+       z foo	 cd to most frecent dir matching foo
        z foo bar cd to most frecent dir matching foo and bar
-       z -r foo  cd to highest ranked dir matching foo
-       z -t foo  cd to most recently accessed dir matching foo
-       z -l foo  list all dirs matching foo (by frecency)
+       z -r foo	 cd to highest ranked dir matching foo
+       z -t foo	 cd to most recently accessed dir matching foo
+       z -l foo	 list all dirs matching foo (by frecency)
 
 
 NOTES
        Installation:
 
+       optionally:
+	set $_Z_CMD in .bashrc/.zshrc to change the command (default z).
+
        put something like this in your $HOME/.bashrc:
 
-        . /path/to/z.sh
+	. /path/to/z.sh
 
        put something like this in your $HOME/.zshrc:
 
-        . /path/to/z.sh
-        function precmd () {
-          z --add "$(pwd -P)"
-        }
+	. /path/to/z.sh
+	function precmd () {
+	  _z --add "$(pwd -P)"
+	}
 
        cd around for a while to build up the db.
+
        PROFIT!!
 
        Frecency:
 
-       Frecency is a portmantaeu of 'recent' and 'frequency'. It is a weighted
-       rank  that depends on 'how often' and 'how recently' something occured.
-       As far as I know, Mozilla came up with the term.
+       Frecency is a portmantaeu of 'recent' and 'frequency'. It  is  a	 weighted
+       rank  that depends on how often and how recently something occured. As far
+       as I know, Mozilla came up with the term.
 
-       In z, a directory that has low ranking but has been  accessed  recently
-       will  quickly  have  higher rank than a directory accessed frequently a
-       long time ago.
+       In z, a directory that has low ranking but has been accessed recently will
+       quickly	have higher rank than a directory accessed frequently a long time
+       ago.
+
+
+ENVIRONMENT
+       A function _z() is defined.
+
+       An alias $_Z_CMD='_z 2>&1' is defined. If not set, $_Z_CMD defaults to z.
 
 
 FILES
@@ -75,4 +85,4 @@ SEE ALSO
 
 
 
-z                                February 2011                            Z(1)
+z				  February 2011				     Z(1)
diff --git a/z.1 b/z.1
index c774f70..ca85648 100644
--- a/z.1
+++ b/z.1
@@ -39,30 +39,41 @@ directory that matches ALL of the regexes given on the command line.
 
 \fBInstallation:\fR
 .P
-put something like this in your $HOME/.bashrc:
+optionally:
+ set \fB$_Z_CMD\fR in .bashrc/.zshrc to change the command (default \fBz\fR).
 .P
- . /path/to/z.sh
+put something like this in your \fB$HOME/.bashrc\fR:
 .P
-put something like this in your $HOME/.zshrc:
+ \fB. /path/to/z.sh\fR
 .P
- . /path/to/z.sh
+put something like this in your \fB$HOME/.zshrc\fR:
+.P
+ \fB. /path/to/z.sh
  function precmd () {
-   z --add "$(pwd -P)"
- }
+   _z --add "$(pwd -P)"
+ }\fR
+.P
+\fBcd\fR around for a while to build up the db.
 .P
-cd around for a while to build up the db.
-.br
 PROFIT!!
+.br
 
 \fBFrecency:\fR
 .P
 Frecency is a portmantaeu of 'recent' and 'frequency'. It is a weighted rank
-that depends on 'how often' and 'how recently' something occured. As far as I
+that depends on how often and how recently something occured. As far as I
 know, Mozilla came up with the term.
 .P
 In \fBz\fR, a directory that has low ranking but has been accessed recently
 will quickly have higher rank than a directory accessed frequently a long time
 ago.
+.br
+
+.SH ENVIRONMENT
+A function \fB_z()\fR is defined.
+.P
+An alias \fB$_Z_CMD\fR='_z 2>&1' is defined. If not set, \fB$_Z_CMD\fR defaults
+to \fBz\fR.
 
 .SH FILES
 data is stored in \fB$HOME/.z\fR
diff --git a/z.sh b/z.sh
index 6bcc4cf..9d4dc2b 100755
--- a/z.sh
+++ b/z.sh
@@ -3,12 +3,14 @@
 # maintains a jump-list of the directories you actually use
 #
 # INSTALL:
+#   * optionally:
+#     set $_Z_CMD in .bashrc/.zshrc to change the command (default z).
 #   * put something like this in your .bashrc:
 #     . /path/to/z.sh
 #   * put something like this in your .zshrc:
 #     . /path/to/z.sh
 #     function precmd () {
-#       z --add "$(pwd -P)"
+#       _z --add "$(pwd -P)"
 #     }
 #   * cd around for a while to build up the db
 #   * PROFIT!!
@@ -20,7 +22,7 @@
 #   * z -t foo  # cd to most recently accessed dir matching foo
 #   * z -l foo  # list all dirs matching foo (by frecency)
 
-z() {
+_z() {
 
  local datafile="$HOME/.z"
 
@@ -166,18 +168,20 @@ z() {
  fi
 }
 
+alias ${_Z_CMD:-z}='_z 2>&1'
+
 if complete &> /dev/null; then
   # bash tab completion
-  complete -C 'z --complete "$COMP_LINE"' z
+  complete -C '_z --complete "$COMP_LINE"' ${_Z_CMD:-z}
   # populate directory list. avoid clobbering other PROMPT_COMMANDs.
-  echo $PROMPT_COMMAND | grep -q "z --add"
-  [ $? -gt 0 ] && PROMPT_COMMAND='z --add "$(pwd -P 2>/dev/null)" 2>/dev/null;'"$PROMPT_COMMAND"
+  echo $PROMPT_COMMAND | grep -q "_z --add"
+  [ $? -gt 0 ] && PROMPT_COMMAND='_z --add "$(pwd -P 2>/dev/null)" 2>/dev/null;'"$PROMPT_COMMAND"
 elif compctl &> /dev/null; then
   # zsh tab completion
   _z_zsh_tab_completion() {
     local compl
     read -l compl
-    reply=(${(f)"$(z --complete "$compl")"})
+    reply=(${(f)"$(_z --complete "$compl")"})
   }
-  compctl -U -K _z_zsh_tab_completion z
+  compctl -U -K _z_zsh_tab_completion ${_Z_CMD:-z}
 fi