References can be defined to point users to additional information. The references are formatted with the prefix before the argument that is used to create the argument (e.g. "bid,39545" creates a link to BugTraq writeup for issue 39545).
Generic URLs can be created with the url prefix (e.g. "url,google.com" creates a link to Google.com).
The following types of references exist:
| Name | Prefix | Links To |
| BuqTraq | bugtraq | http://www.securityfocus.com/bid |
| CVE | cve | http://cve.mitre.org/cve/ |
| Nessus | nessus | http://www.nessus.org/plugins/index.php?view=all |
| Arachnids | arachnids | (URL is now defunct, don't use this anymore) |
| McAfee | mcafee | http://vil.nai.com/vil/default.aspx |
| URL | url | |
| OSVDB | osvdb | http://osvdb.org/show/osvdb |
| USN | usn | http://www.ubuntu.com/usn/ |
| Milw0rm | milworm | http://milw0rm.com/exploits |
| Secunia | secunia | http://secunia.com/advisories/ |
| RHSA | rhsa | http://rhn.redhat.com/errata/ |
| Microsoft KB | microsoft_kb | http://support.microsoft.com/kb/ |
| Microsoft Security Bulletin | microsoft_bulletin | http://www.microsoft.com/technet/security/bulletin/ |