S: (n) quorum (a gathering of the minimal number of members of an organization to conduct business)
S: (n) membership, rank (the body of members of an organization or group) "they polled their membership"; "they found dissension in their own ranks"; "he joined the ranks of the unemployed"
S: (n) federation (the act of constituting a political unity out of a number of separate states or colonies or provinces so that each member retains the management of its internal affairs)