diff -r 67567d7f1174 -r 48b30ff742cb README
--- a/README	Tue Aug 06 15:06:27 2019 +0200
+++ b/README	Tue Aug 06 15:06:38 2019 +0200
@@ -145,3 +145,23 @@
 test output change from a changeset in core should adds the following line to their description:
 
 CORE-TEST-OUTPUT-UPDATE: <CORE-NODE-ID>
+
+
+Format-source config
+====================
+
+Format source helps smooth out the pain of merging after auto-formatting.
+Follow the instructions for install here:
+
+.. _`format-source`: https://bitbucket.org/octobus/format-source
+
+Then update both your global and repo config files::
+
+    $ hg config -l # add the lines below
+    [extensions]
+    formatsource =
+
+    [format-source]
+    byteify-strings = python3 ~/workspace/octobus/mercurial-devel/contrib/byteify-strings.py --dictiter --treat-as-kwargs kwargs opts commitopts TROUBLES --allow-attr-methods
+    byteify-strings:mode.input = file
+    byteify-strings:mode.output = pipe