Data Definition for Cluster Objects 
Use
The Data Definition function is only valid for
cluster objects.This function allows you to change the name of a
data definition include for a cluster object.If you create a new database object or cluster object for the interface format, the Interface Toolbox requires the following information:

If you change the name of the data definition include you should ensure that the new data definition include contains at least all the data definitions from the old include.
Activities
Either
change the name of a data definition include or display the include.