Of the tendencies listed, only the reunified Fourth International claims to be the original Fourth International. Certain tendencies which claim to be Trotskyist make no attempt to claim any relationship to the Fourth International in an organisational sense and argue that it no longer exists. Some claim to represent a continuity from the Fourth International or to have re-established it. Others argue that the title "Fourth International" is so discredited that a Fifth International or another new organization is needed.
The various tendencies listed here range in size from those having thousands of adherents in dozens of countries to tendencies which can barely claim a dozen members in three or four countries.
There are also international groupings around some Trotskyist groups which have no formal international structure: