Final answer:
An endorsement found in an insurance plan which modifies the provisions of the policy is called a rider. Riders are used to customize insurance policies to better suit the policyholder's needs.
Step-by-step explanation:
An endorsement found in an insurance plan which modifies the provisions of the policy is called a rider. A rider is an add-on to the policy that provides additional coverage or modifies the terms and conditions. For example, an insurance policy may have a standard coverage limit for jewelry, but a rider can be added to increase that limit specifically for valuable pieces.
Riders are used to customize insurance policies to better suit the policyholder's needs. They can also be used to exclude certain risks or include additional risks that are not covered by the standard policy. Riders provide flexibility and allow policyholders to tailor their insurance coverage.