Provides a list of all potentially dead data items in the program. 
                  	  A data item is regarded as dead if neither it, nor any of its related data items, are referenced in the Procedure Division.
               This generally gives a very good indication of whether an item declared in the Data Division is actually required by the program
               or not. Care should be taken with: 
               
            
 
            	 
             
               		
                
                  		  
                  - Data items used by conditionally compiled code. 
                     		  
                  
- Data items defined in special clauses and not referenced explicitly in the Procedure Division (for example, FILE STATUS IS
                     ...) and Screen Section (TO, FROM).