diff --git a/hgext3rd/gitlookup.py b/hgext3rd/gitlookup.py
--- a/hgext3rd/gitlookup.py
+++ b/hgext3rd/gitlookup.py
@@ -4,22 +4,30 @@
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
-#
-# This will look up hashes from an hg-git map file over the wire. Define the
-# location of the map file with the gitlookup.mapfile config option, then use
-# thus:
-#
-# - get the git equivalent of hg 47d743e068523a9346a5ea4e429eeab185c886c6
-#       hg identify --id\
-#                   -r _gitlookup_hg_47d743e068523a9346a5ea4e429eeab185c886c6\
-#                   ssh://server/repo
-# - get the hg equivalent of git 6916a3c30f53878032dea8d01074d8c2a03927bd
-#     hg identify --id\
-#                 -r _gitlookup_git_6916a3c30f53878032dea8d01074d8c2a03927bd\
-#                 ssh://server/repo
-#
-# This also provides client and server commands to download all the Git metadata
-# via bundle2.
+
+''' extension that will look up hashes from an hg-git map file over the wire.
+    This also provides client and server commands to download all the Git
+    metadata via bundle2. Example usage:
+
+    - get the git equivalent of hg 47d743e068523a9346a5ea4e429eeab185c886c6
+
+        hg identify --id -r\\
+            _gitlookup_hg_47d743e068523a9346a5ea4e429eeab185c886c6\\
+            ssh://server/repo
+
+    - get the hg equivalent of git 6916a3c30f53878032dea8d01074d8c2a03927bd
+
+        hg identify --id -r\\
+            _gitlookup_git_6916a3c30f53878032dea8d01074d8c2a03927bd\\
+            ssh://server/repo
+
+::
+
+    [gitlookup]
+    # Define the location of the map file with the mapfile config option.
+    mapfile = <location of map file>
+
+'''
 
 from mercurial import bundle2, exchange, encoding, extensions, hg
 from mercurial import localrepo, util, wireproto, error, registrar