Taken from the the Lochac seneschal's page on [Hamlets]
A hamlet is a social group within the game, but is not a formal SCA entity in the same sense as a Shire, Canton or Barony. It has a minimum membership of five people. It is easiest to think of a hamlet as the next step up from a household - but it is distinct from a household because, once established, it is a recognised entity that is not tied to any one person or family. A hamlet can exist within the territory of a Barony or a Shire, but a hamlet cannot be created inside a hamlet. Hamlets are created by the Crown, under advice from the Kingdom Seneschal and, if they are within a Barony, the relevant Baron and Baroness.