Changes

Mail is handled according to a category, such as general [[letter]], media mail, [[postcard]] or package. Each category has restrictions on content, weight, [[dimension]]s and is charged accordingly. Although the USPS Inspector General checks scales and other measuring devices for accuracy, federally owned post offices are exempt from the state inspections that private companies are subject to. Private companies' measuring devices are typically inspected regularly by an internal department within the company and at least once a year by individual states' bureau of weights and measures, often a division of that state's department of agriculture.

* [[Fedex]] and [[UPS]]

* [[Supply chain]] and [[Just in time|Just in Time]] distribution system