diff --git a/core/modules/filters.js b/core/modules/filters.js
index 0cd0d2dbd..2c23ee297 100644
--- a/core/modules/filters.js
+++ b/core/modules/filters.js
@@ -12,6 +12,9 @@ Adds tiddler filtering methods to the $tw.Wiki object.
 /*global $tw: false */
 "use strict";
 
+/* Maximum permitted filter recursion depth */
+var MAX_FILTER_DEPTH = 300;
+
 /*
 Parses an operation (i.e. a run) within a filter string
 	operators: Array of array of operator nodes into which results should be inserted
@@ -341,7 +344,7 @@ exports.compileFilter = function(filterString) {
 		}
 		var results = new $tw.utils.LinkedList();
 		self.filterRecursionCount = (self.filterRecursionCount || 0) + 1;
-		if(self.filterRecursionCount < 300) {
+		if(self.filterRecursionCount < MAX_FILTER_DEPTH) {
 			$tw.utils.each(operationFunctions,function(operationFunction) {
 				operationFunction(results,source,widget);
 			});
diff --git a/editions/test/tiddlers/tests/data/filters/Recursion.tid b/editions/test/tiddlers/tests/data/filters/Recursion.tid
new file mode 100644
index 000000000..13d80e521
--- /dev/null
+++ b/editions/test/tiddlers/tests/data/filters/Recursion.tid
@@ -0,0 +1,15 @@
+title: Filters/Recursion
+description: Filter recursion detection
+type: text/vnd.tiddlywiki-multiple
+tags: [[$:/tags/wiki-test-spec]]
+
+title: Output
+
+\whitespace trim
+\define myfilter() [subfilter<myfilter>]
+
+<$text text={{{ [subfilter<myfilter>] }}}/>
++
+title: ExpectedResult
+
+<p>/**-- Excessive filter recursion --**/</p>
\ No newline at end of file
diff --git a/editions/test/tiddlers/tests/data/transclude/Recursion.tid b/editions/test/tiddlers/tests/data/transclude/Recursion.tid
index 23ec97b13..d75e671eb 100644
--- a/editions/test/tiddlers/tests/data/transclude/Recursion.tid
+++ b/editions/test/tiddlers/tests/data/transclude/Recursion.tid
@@ -6,11 +6,7 @@ tags: [[$:/tags/wiki-test-spec]]
 title: Output
 
 \whitespace trim
-\procedure recurse(a:0)
-<$transclude $variable="recurse" a={{{ [<a>add[1]] }}}/>
-\end
-
-<<recurse>>
+<$transclude $tiddler="Output"/>
 +
 title: ExpectedResult
 
diff --git a/editions/tw5.com/tiddlers/widgets/LetWidget.tid b/editions/tw5.com/tiddlers/widgets/LetWidget.tid
index b66fed0fd..b27306cfb 100644
--- a/editions/tw5.com/tiddlers/widgets/LetWidget.tid
+++ b/editions/tw5.com/tiddlers/widgets/LetWidget.tid
@@ -1,6 +1,6 @@
 title: LetWidget
-created: 20220502144738010
-modified: 20220502144738010
+created: 20211028115900000
+modified: 20221001094658854
 tags: Widgets
 caption: let
 
@@ -13,12 +13,12 @@ caption: let
 The content of the <<.wid let>> widget is the scope for the value assigned to the variable.
 
 |!Attribute |!Description |
-|//{any attributes}// |Each attribute name specifies a variable name. The attribute value is assigned to the variable |
-
-<<.from-version "5.3.0">> Previously, variable names were restricted to not start with a dollar sign. That restriction is no longer applied.
+|//{attributes}// |Each attribute name specifies a variable name. The attribute value is assigned to the variable |
 
 Attributes are evaluated in the order they are written. Attributes with the same name are allowed. Each time a duplicate attribute is encountered, it will replace the existing value set by the earlier duplicate.
 
+<<.note """<<.from-version "5.2.4">> There is no longer any restriction on using variable names that start with the $ character.""">>
+
 ! Examples
 
 Consider a case where you need to set multiple variables, where some depend on the evaluation of others.