F.A.Q. This section provides answers to common questions about our data services. What are the benefits of NCOALink? What are the requirements for NCOALink? How does NCOALink work? What are the limitations of NCOALink? What is Delivery Point Validation (DPV)? What is the Locatable Address Conversion System (LACS)? What is Preprocessing Optimization? What is eXtended Change of Address (XCOA)?