diff --git a/docs/CONTRIBUTING b/docs/CONTRIBUTING
index ba26d33..ecc1c10 100644
--- a/docs/CONTRIBUTING
+++ b/docs/CONTRIBUTING
@@ -30,6 +30,7 @@
 Comments
 --------
 We only use plain old /* C standard comments */.
+If you want to comment out large blocks containing other comments, use #if 0.
 
 Style
 -----