The Commercial Internet Protocol Security Option Working Group is chartered to define an IP security option that can be used to pass security information within and between security domains. This new security option will be modular in design to provide developers with a single software environment which can support multiple security domains. The CIPSO protocol will support a large number of security domains. New security domains will be registered with the Internet Assigned Numbers Authority (IANA) and will be available with minimal difficulty to all parties. There is currently in progress another IP security option referred to as IPSO (RFC 1108). IPSO is designed to support the security labels used by the US Department of Defense. CIPSO will be designed to provide labeling for the commercial, US civilian and non-US communities. The Trusted Systems Interoperability Group (TSIG) has developed a document which defines a structure for the proposed CIPSO option. The working group will use this document as a foundation for developing an IETF CIPSO specification.