Cross-references in oracle...

Cross-reference types define relationships between items and entities such
     as old item numbers or supplier item numbers.
     
     For example, you can create a cross-reference type Old to track the old
     item numbers, and a type Supplier to track supplier part numbers.
     
     To define a cross-reference type:
          
          1. Navigate to the Cross-Reference Types window:
            
             Inventory>Items>Cross References
          
          2. Enter a unique cross-reference type name.
          
          3. Save your work.
     
     To make a cross-reference type inactive:
            
            o    Enter the date on which the cross-reference type becomes inactive.
          
          As of this date, you cannot assign this cross-reference type to an
          item.
     
     To delete a cross-reference type:
            
            o    You can delete a cross-reference if any item has not used it.
     
     To assign a cross-reference type:
            
            o    Choose the Assign button.