The Membership is composed of all the Institute’s Fellows and Observers. Observers have a right to participate in meetings and to speak, but not to vote. The main functions of the Membership are to elect the members of the Council and to approve the results of ELI projects carried out under the regular procedure. An ordinary meeting of the Membership is called every year to discuss the progress made by the Institute and the various committees. An extraordinary meeting of the Membership may be called by the Executive Committee if required. The Executive Committee is obliged to call an extraordinary Membership meeting when at least 200 Members or one-fifth of the Members, whichever is the lesser, so request in writing.