--- a/README	Wed May 31 14:36:25 2017 +0200
+++ b/README	Thu Jun 01 02:28:36 2017 +0200
@@ -105,9 +105,18 @@
     $ cd tests
     $ python $HGSRC/tests/run-tests.py
 
-(evolve's stable and default branches correspond to Mercurial's stable
-and default branches. So to test evolve from default, you need
-Mercurial on default.), Older version of Mercurial are supportd on their respective ``mercurial-x.y`` branches.
+Branch policy
+-------------
+
+The evolve test are highly impacted by changes in core. To deal with this, we use named branches.
+
+There are two main branches: "stable" and "default". Tests on these branch are
+supposed to pass with the corresponding "default" and "stable" branch from core
+Mercurial.
+
+In addition, we have compatibility branches to check tests on older version of
+Mercurial. They are the "mercurial-x.y" branches. They are used to apply
+expected test change only, no code change should happen there.
 
 Changelog
 =========