The relationship between a property and an address is many-to-many. In DC a SSL (Square, Suffix, Lot) is used to identify a property. One SSL can have multiple addresses located on it. This often includes garden-style apartment complexes as well as corner buildings with separate addresses facing each adjacent street. One address can also sit upon multiple SSLs. One single family residence can sit upon multiple lots. The cross reference table contains the many-to-many relationship between address IDs and SSLs. [A small percentage of addresses do not have an associated SSL (such as metro entrances or many addresses on Federal property.] Use this cross reference table to relate the District's address points in the Master Address Repository (MAR) with the SSLs and vice versa.