diff --git a/core/modules/parsers/newwikitextparser/rules/classrun.js b/core/modules/parsers/newwikitextparser/rules/classrun.js
new file mode 100644
index 000000000..376dac6de
--- /dev/null
+++ b/core/modules/parsers/newwikitextparser/rules/classrun.js
@@ -0,0 +1,41 @@
+/*\
+title: $:/core/modules/parsers/newwikitextparser/rules/classrun.js
+type: application/javascript
+module-type: wikitextrule
+
+Wiki text run rule for assigning classes to paragraphs and other blocks. For example:
+
+{{{
+{{myClass{This text will have the CSS class `myClass`.
+
+* This will not be recognised as a list
+
+List item 2}}}
+}}}
+
+
+\*/
+(function(){
+
+/*jslint node: true, browser: true */
+/*global $tw: false */
+"use strict";
+
+exports.name = "class";
+
+exports.runParser = true;
+
+exports.regExpString = "\\{\\{(?:[^\\{\\r\\n]+)\\{";
+
+exports.parse = function(match,isBlock) {
+	var tree,
+		reStart = /\{\{([^\{\r\n]+){/mg,
+		reEnd = /(\}\}\})/g;
+	reStart.lastIndex = this.pos;
+	match = reStart.exec(this.source);
+	this.pos = match.index + match[0].length;
+	tree = this.parseRun(reEnd,{leaveTerminator: false});
+	return [$tw.Tree.Element("span",{"class":match[0]},tree)];
+};
+
+})();