Others engage in spoofing of email addresses (much easier than IP address spoofing). IPv4 address exhaustion is the depletion of the pool of unallocated IPv4 addresses. The address block is reserved by IANA for Unique Local Addresses (ULA). This information includes the endpoint IP addresses and port numbers. The information included home addresses and phone numbers. DNS serves other purposes in addition to translating names to IP addresses. Blocks are addressed using their logical block addresses (LBA). There is ambiguity about how private IP addresses are. They are identified by hostnames and network addresses. Current US Code addresses air travel specifically. These include IP addresses, routing commands, and a few connection options. Albuquerque is geographically divided into four quadrants that are officially part of mailing addresses. The Google service also addresses DNS security. This process directly addresses maintenance preventable failures. PO box addresses have postal codes which differ from those used for street addresses.