List Hygiene Services Improve your deliverability rate and keep mailing costs down by using our List Hygiene services.  Eliminate bad addresses and increase your response rates.  Keep your files up to date and stop mailing to the wrong prospects. Merge / Purge      - Consolidate files and eliminate duplicate records. Data Consolidation and Standardization      - Validate and correct address components, enhance ZIP+4 Codes and more. NCOA: The National Change of Address       - Update your mailing list with the latest change of address filed with the USPS. DSF: Delivery Sequence File      - Assigns ZIP+4 and standardizes mailing addresses. LACS: Locatable Address Conversion System      - Updates rural addresses to city-style addresses. CASS: Coding Accuracy Support System      - improves the accuracy of 5-digit ZIP, ZIP+4, carrier route, and delivery point bar codes. Deceased File Processing      - Eliminates deceased individuals from your database. Do Not Call Processing      - Removes or flags phone numbers on the Do Not Call list.