(1)The legal right conferred by a person or institution upon another to act in the former's stead. (2) In the securities industry, a limited power of attorney given by a customer to a representative of a broker/dealer would normally give a registered representative trading discretion over the customer's account. The power is limited in that neither securities nor funds may be withdrawn from the account. (3) In the securities industry, an unlimited power of attorney given by a customer to a representative o a broker/dealer would normally give a registered representative full discretion over the conduct of the customer's account.