an individual who accompanies diplomatic mail. In the fulfillment of his duties a diplomatic courier enjoys the protection of the state to which he is sent and has personal immunity. (He may not be arrested or detained in any way.) In the practice of a number of states there is another individual who assists the diplomatic courier and has the same status.
The country that sends the diplomatic courier gives him a courier’s list and a passport confirming his status. The state to which he is sent is obliged to guarantee the protection of the diplomatic courier on its territory and to give him all kinds of assistance in fulfilling his official functions. In the USSR this obligation is stipulated by the Regulation on Diplomatic and Consular Representatives of Foreign States on the Territory of the USSR of May 23, 1966.
If the diplomatic mail is transported on a special aircraft, the pilot is the diplomatic courier. Similarly, the driver of a motor vehicle that is carrying diplomatic mail is a diplomatic courier. Most states consider the diplomatic courier a diplomat and make him exempt from taxes, customs duties, and the examination of his personal effects.