As argued in the previous chapter, every organisation is a group, with members who recognise it and their own membership of it. Organisations are also always networks of reciprocal identification: self-definition as a member depends upon recognition by other members. Specifically, membership must at least be registered by those who are authorised to do so (i.e. by ‘the organisation’). Hierarchies of authority and control govern the reciprocity of identification within organisations, and group membership is always in part a matter of categorisation. Thus it is even, in extremis, possible to have organisational ‘members’ who are authoritatively registered as such, but are not themselves aware of their ‘membership’, or may not even exist.