The Chatham House Rule reads, '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'. The rule may be invoked at meetings to encourage openness and the sharing of information. It was devised in 1927 and revised in 1992 and 2002.