A more thorough explanation:

Definition: An allograph is a written representation of an agent's signature or handwriting on behalf of a principal. It is the opposite of an autograph, which is a person's own signature or handwriting.

Example: When a celebrity hires an assistant to sign autographs on their behalf, the assistant's signature is considered an allograph.

Explanation: In this example, the celebrity is the principal and the assistant is the agent. The assistant is writing the celebrity's name in a way that resembles their signature, but it is not the celebrity's actual handwriting. This is an example of an allograph because it is a representation of the principal's signature, but it is not the principal's own handwriting.