Chatham House Rule
When a meeting, or part thereof, is held under the Chatham House Rule, participants are free to use the information received, but neither the identity nor the affiliation of the speaker(s), nor that of any other participant, may be revealed.
A Chatham House-sponsored meeting need not be at Chatham House physically for the rule to be assumed as the default. Specific Chatham House meetings may be "off the record" as a stricter criterion, or may be designated as public Members Meetings.
It was created in 1927 and refined in 1992 and 2002. Chatham House can discipline members that break the Rule, although other organizations may use the rule but have none other than moral sanctions.
Chatham House observe that the spirit of the rule is the important aspect: "For example, sometimes speakers need to be named when publicizing the meeting. The Rule is more about the dissemination of the information after the event - nothing should be done to identify, either explicitly or implicitly, who said what." A list of attendees, however, may not be published.
Many professional meetings cite the rule, or variants of it; journalists have assorted formulas for "background". Deep background is essentially the Rule, while shallow background could allow affiliation but not name, such as "a senior government official."
- Chatham House Rule, Chatham House