The Post Office loves acronyms. That's why SmartyStreets has products with CASS, LACSLink, and DPV in their names. Other products and services that you might hear connected with the USPS are NCOA, PAVE, and MASS. Even 'ZIP' in ZIP Code is an acronym for "Zoning Improvement Plan." It can seem like the post office has its own language sometimes.
Some of these acronyms are more interesting and confusing than others. One of the questions we get a lot is, "What is LACSLink?" 'LACS' is an acronym for "Locatable Address Conversion System." A "Locatable Address" has reference to a 9-1-1 system. It means that addresses are named and numbered in such a way that shortens response times to emergencies.
In many areas of the country, rural route addresses have been used to deliver mail in the past. As these areas adopt 9-1-1 systems, the rural route addresses are replaced by locatable addresses. For a few years, the Post Office will continue to deliver mail to the rural route, but eventually it will be returned as "Undeliverable As Addressed" to the mailer. That's where LACSLink comes into play.
LACSLink is a system that converts addresses that have been renamed or renumbered into locatable addresses. This is an invaluable service for those who send out bulk mail, because you might otherwise lose contact with many of your contacts.