How to identify if <some:element> is a tag handler or a component handler during the development process (e.g. in Eclipse)? As of "Mastering JavaServer Faces 2.2" (Anghel Leonard) p. 538, <ui:repeat> is a component handler whereas <ui:include> is a tag handler. But during development I don't see any difference but the ignorance of that existing difference may lead to serious application errors.
during the development process
The quickest way is to try setting the rendered attribute to false.
<ui:repeat ... rendered="false">
...
</ui:repeat>
<ui:include ... rendered="false">
...
</ui:include>
If that works, i.e. the output suddenly disappears when refreshing the page in your favorite web browser, then it's an UIComponent. If that doesn't work, then it's a TagHandler.
This is because the rendered (and binding and id) attributes are only defined in the UIComponent superclass.