diff --git a/README.md b/README.md
index 97e6c4f..3f25b10 100644
--- a/README.md
+++ b/README.md
@@ -38,7 +38,8 @@ the most recent release.
 The prior 2.x and 1.x versions are available as release branches for
 tracking and possible back-porting of relevant fixes. Branch layout is:
 
-    master <- 3.x, at present
+    master         <- 3.x, at present
+    v3.x.x            pre-release branches, used for staging branches
     release/2.x
     release/1.x