ARIN is a Regional Internet Registry.
They oversee the allocation and registration of Internet number resources in their region (America).
ARIN offers a “web-based” interface to Whois data at http://whois.arin.net
Networks and ASNs are collectively referred to as resources in ARIN parlance. They are the pieces of information assigned or allocated to organizations for the coordinated administration and operation of the Internet.
ARIN’s data model has six types of addressable resources. 1) These are reflected in Whois-RWS in the following way:
Example for a poc
xmllint --format http://whois.arin.net/rest/poc/KOSTE-ARIN