Beginning with participation in the Cape Spartel Light Convention of May 31, 1865, the United States has become a party to about a hundred multipartite administrative treaties, including revisions and amendments of the same. The number of parties to a treaty varies with the treaty, from three or four, as in the case of the Fur Seals Convention of July 7, 1911, to ninety, as in the case of the Universal Postal Convention concluded at Cairo, March 20, 1934. The agreements, usually technical in character, deal with a variety of humanitarian, economic, and cultural subjects, ranging from agriculture to whales. Many of these agreements, such as those dealing with postal matters, publicity of customs documents, and publication of customs tariffs, are primarily of concern to administrative services.