Codes are enforced by state or local officials through the modality of reviewing building plans or conducting inspections—the ADA does not practice these. To mitigate issues with compliance, states are allowed to submit requests for the DOJ to review if all state and local accessibility laws meet or exceed the requirements of the ADA. This is helpful to ensure that all laws and standards are met, as it may catch errors or failures. It can also be used as legal evidence in response to a challenge.