A more thorough explanation:

Definition: Policy proof of interest is evidence that a person making an insurance claim has an insurable interest in the loss. This evidence is shown by possession of a policy. It is abbreviated as PPI.

Example: Let's say John buys a life insurance policy and names his wife, Jane, as the beneficiary. If John were to pass away, Jane would be able to make a claim on the policy. However, if Jane did not have an insurable interest in John's life (e.g. they were divorced), she would not be able to make a claim. Possession of the policy serves as evidence that Jane has an insurable interest in John's life.

Explanation: The example illustrates how possession of a policy serves as evidence of an insurable interest. In this case, the life insurance policy serves as proof that Jane has an insurable interest in John's life. Without possession of the policy, Jane would not be able to make a claim on the policy.