diff --git a/editions/tw5.com/tiddlers/systemtags/SystemTag_ $__tags_ClassFilters_TiddlerTemplate.tid b/editions/tw5.com/tiddlers/systemtags/SystemTag_ $__tags_ClassFilters_TiddlerTemplate.tid
index 49ad90100..245e7cbdb 100644
--- a/editions/tw5.com/tiddlers/systemtags/SystemTag_ $__tags_ClassFilters_TiddlerTemplate.tid	
+++ b/editions/tw5.com/tiddlers/systemtags/SystemTag_ $__tags_ClassFilters_TiddlerTemplate.tid	
@@ -1,9 +1,14 @@
 caption: $:/tags/ClassFilters/TiddlerTemplate
 created: 20221020035738692
 description: marks filters evaluated to dynamically add classes to the page template.
-modified: 20221020035933363
+modified: 20230326153057521
 tags: SystemTags
 title: SystemTag: $:/tags/ClassFilters/TiddlerTemplate
 type: text/vnd.tiddlywiki
 
 The [[system tag|SystemTags]] `$:/tags/ClassFilters/TiddlerTemplate`  marks filters evaluated to dynamically add their output as CSS classes to the tiddler template.
+
+The variables available are within each filter:
+
+* <<.var storyTiddler>>: the tiddler in the story for which the filter should be evaluated.
+* <<.var currentTiddler>>: the tiddler holding the filter definition being evaluated.