diff --git a/data/category-media-ru-blocked b/data/category-media-ru-blocked
index f958bb78..09cf6779 100644
--- a/data/category-media-ru-blocked
+++ b/data/category-media-ru-blocked
@@ -1,3 +1,6 @@
+# Media sites blocked in Russia
+# source: https://ru.wikipedia.org/wiki/Список_заблокированных_в_России_СМИ
+
 24.kg
 9tv.co.il
 activatica.org