Nationally, the Petroleum Program run by weights and measures in California is unique. Locally, weights and measures officials enforce that portion of the California Business and Professions code relating to petroleum product quality standards. From time to time, random samples are taken to ensure product compliance with national standards. Undercover purchases are made to investigate consumer complaints and to inspect the accuracy of the transactions. Undercover purchases also serve as a method for gathering samples of products used for determining compliance with standards. Labeling regulations are also strictly enforced to provide product identity and information to the seller and consumer.