id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
12501	rulePattern does not allow custom elements like <custom-tag>	Leon Machens	Piotrek Koszuliński	"Custom elements are described [http://w3c.github.io/webcomponents/spec/custom/ here].
Due to the rulePattern in filter.js it is not possible to use elements with a  minus-character.

A simple solution is to edit the pattern to:

{{{
var rulePattern = /^([a-z0-9-*\s]+) ...
}}}"	Bug	closed	Normal	CKEditor 4.4.6	General	4.1	fixed