I\'m using two elements inside a .
I can reproduce it in 2.1.24. I'm not sure if this is a bug in Facelets' SAX parser but it indeed look much like that it got confused in nested namespaces. You're with <svg xmlns> declaring a new default XML namespace which has seemingly overriden the <html xmlns> one for HTML tags. I recommend to report this issue to Mojarra guys.
In any case, the right way of using SVG in Facelets is to split off the whole <svg> content into its own .svg file and include it via <ui:include>.
<ul>
<li>
<ui:include src="/resources/svg/one.svg" />
</li>
<li>
<ui:include src="/resources/svg/two.svg" />
</li>
</ul>
This way the namespacing works fine. Additional benefit is, your SVGs are this way instantly reusable.