Publication 28 - Postal Addressing Standards > Appendix E > E1 Format
Alphanumeric ranges present a challenge to the address matching process, whether it is being done on the MLOCR, by a vendor‘s software, or manually. The difficulty in alphanumeric matching is in trying to determine what addresses fall in the range. The following coding rules are being provided to eliminate the inconsistency in the way some of our alphanumeric ranges are coded. The rules that follow apply to both the primary and secondary ranges in street records, rural route box numbers, and highway contract box numbers.
These rules have been developed through meetings, both internal and with some of the major address matching software vendors. We can more accurately match alphanumerics against the ZIP+4 file if they are coded consistently with these rules.