Extend title operator to allow negated form to use multi-valued variables

core/modules/filters/title.js

@@ -16,7 +16,8 @@ exports.title = function(source,operator,options) {
 	var results = [];
 	if(operator.prefix === "!") {
 		source(function(tiddler,title) {
-			if(tiddler && tiddler.fields.title !== operator.operand) {
+			var titleList = operator.multiValueOperands[0] || [];
+			if(tiddler && titleList.indexOf(tiddler.fields.title) === -1) {
 				results.push(title);
 			}
 		});

editions/test/tiddlers/tests/data/multi-valued-variables/MultiValuedNegatedTitle.tid

@@ -0,0 +1,18 @@
+title: MultiValuedVariables/NegatedTitle
+description: Multi-valued operands
+type: text/vnd.tiddlywiki-multiple
+tags: [[$:/tags/wiki-test-spec]]
+
+title: Output
+
+<$let
+	exclude={{{ $:/core Output }}}
+>
+<$text text={{{ [all[tiddlers]!title(exclude)] +[join[-]] }}}/>
+</$let>
++
+title: ExpectedResult
+
+<p>
+ExpectedResult
+</p>

editions/tw5.com/tiddlers/filters/title.tid

@@ -16,4 +16,6 @@ op-neg-output: the input, but with tiddler <<.place T>> filtered out if it exist
 
 <<.op title>> is a [[constructor|Selection Constructors]] (except in the form `!title`), but <<.olink2 "field:title" field>> is a [[modifier|Selection Constructors]].
 
+<<.from-version "5.3.7">> If the operand is quoted with round brackets then the <<.op title>> operator returns the complete list of titles assigned to the multi-valued variable. When negated, the title operator with multi-valued operands returns all the titles that are not present in the operand list.
+
 <<.operator-examples "title">>