roject is a common exchange format used by regional internet registries such as InterNIC
to trade IP address
assignment information. SWIP is what allows you to query a DNS
server with any given section of Class-C IP space using whois
and get back a list of every user in said space. By "user" I mean the actual owners of the IP addresses which are usually companies, organizations, governments or other groups rather than individuals.
See also: X.500