'custom' Example
<HTML XMLNS:CUSTOMTAG> <HEAD> <STYLE> @media all { CUSTOMTAG\:RED { color: red; } CUSTOMTAG\:GREEN { color: green; } CUSTOMTAG\:BLUE { color: blue; } } </STYLE> </HEAD> <BODY> <CUSTOMTAG:RED> CUSTOMTAG:RED tags. </CUSTOMTAG:RED> <CUSTOMTAG:GREEN> closing CUSTOMTAG:GREEN tags. </CUSTOMTAG:GREEN> <CUSTOMTAG:BLUE> CUSTOMTAG:BLUE tags. </CUSTOMTAG:BLUE> </BODY> </HTML>