diff --git a/CLAUDE.md b/CLAUDE.md
index d06d336..705d267 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -145,3 +145,4 @@ When adding new services:
 - Only write code comments when necessary, as the code should be self-explanatory
   (Avoid trivial comment for each code block)
 - Write output messages and code comments in English
+- Omit trailing spaces at the end of lines