How to represent Common Message Model Attribute allowable values?

[dmccutch207]

In the Common Message Model that describes our run-time enterprise-wide UML model, we need to represent allowable values for some attributes.  Currently, we represent allowable values in the Comment field - but we are looking for a systemic way to record these values against their attributes so we can generate them into xsd files.  Ideally, the values would be reusable across attributes so we can share them among sub-classes and track the reuse.

[SVanSchoonlandt]

Not sure about the xsd generation part but for the allowable values would it maybe be possible to setup a new metaclass. Like that all the values are real objects that you can reuse among the different attributes by simply connecting to the attribute. Furthermore you can setup the metaclass in such way that only certain profiles are allowed to add new values and that all users are actually forced to take the predefined values to connect to their attributes.

Instead of creating a new metaclass, maybe the constraint metaclass could be used to achieve the same result.