Change the collection-type of a topic group
Use this procedure to reassign or remove the
            collection-type of a topic group within a reltable cell.
The map must be locked.
        You may at some point want to change a topic goup's
                    collection-type from one type – such as "family" – to another
                valid value: "choice", for example. Or you may want to remove the
                    collection-type attribute altogether. 
collection-type is reassigned and the
            new type appears in the Row Display area.