diff --git a/tool/example.mdn_basedom_list.txt b/tool/example.mdn_basedom_list.txt
index 5bafd821..3fd2663f 100644
--- a/tool/example.mdn_basedom_list.txt
+++ b/tool/example.mdn_basedom_list.txt
@@ -1,3 +1,4 @@
+# Mastodon Preloma Domain
 076.ne.jp
 0j0.jp
 0ko.me