Deputy

One authorized by an officer to exercise the office or right which the officer possesses, for and in place of the latter. A deputy differs from an assignee in that an assignee has an interest in the office itself, and does all things in his own name, for whom his grantor shall not answer except in special cases, but a deputy has not any interest in the office, but is only the shadow of the officer in whose name he acts. And there is a distinction between doing an act by an agent or by a deputy. An agent can only bind his principal when he acts In the name of the principal. But a deputy may do the act, and sign his own name, and bind the principal, for a deputy has in law the whole power of his principal.

Wharton.