diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index f6049b9f97460a0fa7b021bbeb7aca8f8204a054..f6c528479a75f9dc20e4d7ea070b15d4e02c4be5 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -1,3 +1,7 @@
+# Which code branch to use
+
+The master branch is used for code (mostly new features) that shall go into the next major release (e.g. 3.2, 3.3 and so on). The stable branch (e.g. stable-3.1, stable-3.2) is the branch for the current intermediate and bugfix releases. Bugfixes shall be committed to the current stable branch and not the master branch. The stable branch is merged to the master automatically from time to time, please do not submit bugfixes a second time against the master.
+
 # Some guidelines for web development with php.
 -----------------------------------------------------
 * Unix Line Breaks Only, NO windows breaks please.