Incident Object Description Exchange Format
Used for computer security, IODEF ("Incident Object Description Exchange Format") is a data format which is used to describe computer security information for the purpose of exchange between Computer Security Incident Response Teams (CSIRTs). IODEF messages are organized in a human-readable way, and not a machine format. Details of the format are described in RFC 5070 and updated in RFC 6685. Version 2 of the format is defined in RFC 7970, which supersedes the previous version. This RFC presents an implementation of the data model in XML as well as the associated DTD. Further  implementation guidance for IODEF v2 is defined in RFC 8274. One of the main characteristics of IODEF is its compatibility with the IDMEF "Intrusion Detection Message Exchange Format" developed for intrusion detection systems. For this reason, IODEF is heavily based on IDMEF and provides backward compatibility with it. Format. IODEF is an object-oriented structured format, composed of 47 classes in the first version. The IODEF and IDMEF formats having a lot in common: the field structure is similar to the IDMEF one and it is an extensible format: in addition to the usual Additional Data Class, which allow adding  any information relevant to the IODEF message, most enumerations are provided with an "ext" field. This field is used when none of the proposed choices are fitting. Here is a list of the main fields: