 As such, it is particularly unusual among scientific conferences in three ways; it is invitation-only, the invitees come from many different areas of science rather than one subject (such as physics, chemistry or biology), and the meeting has no fixed agenda; the invited scientists, technologists and policy makers set the conference program during the conference itself, based on their shared professional interests and enthusiasms.The first event in 2006 was held under the Chatham House Rule.The policy at the second event was to allow open reporting by default; attendees were expected to indicate if their comments were off the record.