To act on behalf of the administrator of an Identity repository. This is usually achieved by partitioning and filtering the directory and providing simple tools such as web-based functions to add/modify/delete a subset of accounts. It is particularly useful for trusted organisations working as agents on behalf of the owner of the repository, to manage its own staffs access.

The ability to nominate a proxy, representative or agent is a different form of delegation, that usually establishs trust between the entity and another entity (not the service provider). For example allowing an accountant to access some banking records but not to transact, or telling your partner your PIN and giving them use of your ATM card.

Source: http://identityaccessman.blogspot.com/2006/08/identity-dictionary.html