diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index f655a3f..a3b9d57 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -2,5 +2,9 @@
 
 ## Contributing :
 * Open an issue before work to hard
-* Work on the src branch
+* **Work on the src branch**
+* **Use tab for identation**
+* **Preserve identation on empty line**
+* **Test your changes**
 
+- [ ] I've read these rules before submitting my PR.