diff --git a/.claude/skills/git/references/commit.md b/.claude/skills/git/references/commit.md
index b8269974..2efa2b86 100644
--- a/.claude/skills/git/references/commit.md
+++ b/.claude/skills/git/references/commit.md
@@ -53,6 +53,10 @@ test(html): add slider interaction tests
 
 Commits starting with `wip` (case-insensitive) bypass commitlint validation. Use sparingly for work-in-progress that will be squashed.
 
+## No Co-Author Trailers
+
+Do NOT add `Co-Authored-By` trailers to commit messages. The commit author is sufficient attribution.
+
 ## Authoritative Source
 
 See `commitlint.config.js` for the enforced scope list.