I use tagged values for providing downstream hints to general components/templates about how to perform.
An example might be when I am generating an Explorer-style interface, I want different Business Classes to appear differently in the tree.
For instance, I might want customers to be under a node containing the first letter of the company name.
I might want orders grouped into grouped into weekly folders.
Sales areas aren't grouped at all say, just listed under a Sales Area Node which is under a Housekeeping node.
This is an example of using tagged-values for holding configuration items for a general tree-component.
Does anyone else use UML tagged values and if so, what for?