A more thorough explanation:

Proprietary Power

Proprietary power is the legal right or authorization to act or not act, which allows a person or organization to alter legal relations. It is a power coupled with an interest, meaning that the agent has a present interest in the property upon which the power is to operate. This power is irrevocable due to the agent's interest in the subject property and is not held for the benefit of the principal. An example of proprietary power is when a principal borrows money from the agent and authorizes the agent to sell a property if the loan is not repaid and pay himself out of the proceeds.

• A power given to an agent to sell a property if the loan is not repaid and pay himself out of the proceeds.
• A power given to a trustee to manage a trust and make decisions about the trust's assets.

The examples illustrate proprietary power because they are powers coupled with an interest. In the first example, the agent has a present interest in the property upon which the power is to operate, and in the second example, the trustee has an interest in managing the trust's assets. These powers are irrevocable due to the agent's or trustee's interest in the subject property and are not held for the benefit of the principal.