The Unassigned Catalog displays items that correspond to classes created using the WML editor. It serves as a reminder that these items should be placed in a catalog in order to have them appear when the Builder Xcessory is started and reads in your newly-created files. This catalog offers a more limited set of operations appropriate to its nature as a temporary placeholder for icons.
The catalog file is generated from the lower section, to which you can give your own name. To move catalog entries from the upper "holding pen", select MB3 Cut on the item, then, creating a new group if necessary, paste them into the editable catalog.
The catalog as a whole, and the groups and items that you create, have properties that tie them to classes defined in WML and that affect how Builder Xcessory displays them. For a complete description of these properties, see "Item Attributes"and "Groups Attributes" .
Select Properties on the catalog, group, or item to change characteristics. You should give the catalog your choice of names, at least.