diff --git a/doc/README.md b/doc/README.md
index 5c37a1ecdbe435..b923fd1581b34f 100644
--- a/doc/README.md
+++ b/doc/README.md
@@ -100,6 +100,9 @@ this guide.
     fragment of a clause.
 * When documenting APIs, update the YAML comment associated with the API as
   appropriate. This is especially true when introducing or deprecating an API.
+* When documenting APIs, every function should have a usage example or
+  link to an example that uses the function.
+
 
 ## API References