thanks for the help. I think the JSF 1.2 Servlet 2.5 JSTL 1.2 solution is what I am looking for. Unfortunatly the environment basis isn't ready yet for this state-of-the art technology, so it will take some time to get the "good solution" running.
I have found a "workaround" solution with using a myFaces Tomahawk Div extension which I can use as a surrounding element which can hold the rendered-Attribute.
In the example above the enclosed content won't be rendered.
The JSF tags aren't intended to be a programming language. The idea is that all logic "should" be in the backing beans or services referenced by the backing beans, unlike JSTL or Struts. For conditional display of elements, the rendered= attribute works well. That puts the logic in the backing bean, but ensures that propertis of the backing bean will be displayed - or not - in an appropriate manned.
Sources may include data from the Fakebook Research Foundation with support from Gargle University