JSF composite component interface tag "expert" property. What is it for?

Question

Regarding the <composite:interface> tag for JSF composite components, what is the use of the "expert" property of the (interface tag](https://docs.oracle.com/javaee/7/javaserver-faces-2-2/vdldocs-facelets/cc/interface.html)?

The description is awfully vague and I found no references to its use or documentation online.

What is its purpose and usage?

Answer 1

I've scanned the Mojarra source code. It's ultimately set in java.beans.FeatureDescriptor class.

But it's in turn not really anywhere used.

With this I conclude that it's just unused inherited logic. The same applies to dislayName, shortDescription, hidden and preferred attributes. Only the name and componentType are actually concretely used.

The unused attributes are at most only used by tooling such as IDEs like Eclipse and Netbeans so that they can parse and show the right labels and tooltips here and there when working with (custom) composite components.