diff --git a/documentation/content/en/articles/committers-guide/_index.adoc b/documentation/content/en/articles/committers-guide/_index.adoc
--- a/documentation/content/en/articles/committers-guide/_index.adoc
+++ b/documentation/content/en/articles/committers-guide/_index.adoc
@@ -1215,6 +1215,7 @@
 
 This would generate a subtree merge commit of `contrib/mtree` against the local `vendor/NetBSD/mtree` branch.
 If there were conflicts, you would need to fix them before committing.
+Include details about the changes being merged in the merge commit message.
 
 ==== Rebasing your change against latest FreeBSD source tree