diff --git a/editions/tw5.com/tiddlers/mechanisms/Background Actions.tid b/editions/tw5.com/tiddlers/mechanisms/Background Actions.tid
index 07b8e32c4..819582ea1 100644
--- a/editions/tw5.com/tiddlers/mechanisms/Background Actions.tid	
+++ b/editions/tw5.com/tiddlers/mechanisms/Background Actions.tid	
@@ -3,6 +3,12 @@ created: 20250212154426403
 modified: 20250212154426403
 tags: Mechanisms
 
+Background actions are performed whenever there are changes to the results of a filter.
+
+They can be useful for hooking into existing functionality by tracking changes to the tiddler store.
+
+The following example tracks changes to the story list, reusing itself as the text of a notification at the same time:
+
 <<.demo-tiddler """
 title: SampleBackgroundAction: Story Change
 tags: $:/tags/BackgroundAction