ARIN's whois database contains networks, autonomous system (AS) numbers, organizations or customers that are associated with these resources, and related Points of Contact (POC). These are the record types in the database:

• Network (a.k.a. routes, a.k.a. IP address ranges)
• Autonomous systems
• Points-of-contact
• Organizations
• End-user customers routes (SWIPs)

The database can be queried by anyone. One might use the ARIN database to find out who owns a network, in order to discover who to notify about anomalous traffic. The ARIN whois database is often used to pursue hacker attacks. It is important that ARIN's routing registry contain accurate ownership information, so that time and energy is not wasted when hacker attacks are being traced. For instance, UCAR might be unable to trace an attack on UCAR.

To update the ARIN whois database, you send email messages to ARIN. The messages follow a specific format, so that software can parse the messages and update the database. To make messages in the correct format, you get a template message from ARIN and modify it using a text editor.