A document that instructs an agent to buy goods from a named firm is

A document that instructs an agent to buy goods from a named firm is called a "closed indent". It is a type of purchase order that specifies the details of the goods to be purchased, such as the quantity, price, and delivery date. The indent is "closed" because it is issued to a specific supplier or firm, as opposed to an "open indent" which is issued to multiple suppliers for competitive bidding. The closed indent is commonly used in international trade to facilitate the purchase of goods from a foreign supplier through a local agent or middleman.