Answer
· us_addr.cls: used for 'US Streets', 'US One Range', and 'US One Address' styles.
· us_addrc.cls: used for the 'US Alphanumeric Range' styles.
· ny_addr.cls: used for 'US Hyphenated Ranges' styles.
· key_1.cls: used for 'Single Field' style.
· city_st.cls: used for 'US Cities with State' style.
· city_cty.cls: used for 'World Cities with Country' style.
· stmap.cls: used for 'StreetMapTM' style.
· stm_int.cls: used for intersection matching with 'StreetMap' style.
· us_intsc.cls: used for intersection matching with 'US Streets', 'US One Range', and 'US One Address' styles.
· zip.cls and zip4.cls: used for 'ZIP 5Digit' and 'ZIP+4' styles.