diff --git a/g3doc/style-guide.md b/g3doc/style-guide.md
index 421a7d9dc7..9d713c68c9 100644
--- a/g3doc/style-guide.md
+++ b/g3doc/style-guide.md
@@ -62,12 +62,14 @@ in definitions for everything they declare.
 ### `TODO` comments
 
 Follow the [Google styleguide for `TODO` comments][goog-style-todo]. When
-referencing a WebRTC bug, prefer the url form, e.g.
+referencing a WebRTC bug, prefer using the URL form (excluding the scheme part):
 
 ```cpp
 // TODO(bugs.webrtc.org/12345): Delete the hack when blocking bugs are resolved.
 ```
 
+The short form used in commit messages, e.g. `webrtc:12345`, is discouraged.
+
 [goog-style-todo]: https://google.github.io/styleguide/cppguide.html#TODO_Comments
 
 ### Deprecation