Protocol (Fr. protocole, Late Lat. protocollum, from Gr. Ir p&ros, first, and KoXXav, to glue, i.e. originally the first sheet of a papyrus roll), in diplomacy, the name given to a variety of written instruments. The protocollum was under the late Roman Empire a volume of leaves, bound together with glue, in which public acts were recorded, so as to guard against fraud or error on the part of those responsible for preparing them; and in later usage it came to be applied to the original drafts of such acts. Thus, too, the word prothocollare was devised for the process of drawing up public acts in authentic form (Du Cange, Glossarium lat. s.v. Protocollum). The use of the word protocollum for the introductory and other formulae in the medieval diploma (see Diploiiiatic) thus explains itself as implying a recorded usage in such matters.
In the language of modern diplomacy the name of "protocol" is given to the minutes (proces-verbaux) of the several sittings of a conference or congress; these, though signed by the plenipotentiaries present, have only the force of verbal engagements (see Congress). The name of "protocols" is also given to certain diplomatic instruments in which, without the form of a treaty or convention being adopted, are recorded the principles or the matters of detail on which an agreement has been reached, e.g. making special arrangements for carrying out the objects of previous treaties, defining these objects more clearly, interpreting the exact sense of a doubtful clause in a treaty (protocoles interpretatifs) and the like. Thus the famous Troppau protocol, which annunciated the right and duty of the European powers to intervene in the internal affairs of a state threatened with revolution, was from the point of view of its signatories merely a logical application of the principles contained in the treaty of the 20th of November 1815 (see Troppau). Occasionally also an agreement between two or more powers takes the form of a protocol, rather than a treaty, when the intention is to proclaim a community of views or aims without binding them to eventual common action in support of those views or aims; thus the settlement of the question of the Danish succession was recognized by the powers in conference at London, by the protocol of 1852 (see Schleswig-Holstein Question).
Finally, "the protocol" (protocole diplomatique, protocole de chancellerie) is the body of ceremonial rules to be observed in all written or personal official intercourse between the heads of different states or their ministers. Thus the protocol lays down in great detail the styles and titles to be given to states, their heads, and their public ministers, and the honours to be paid to them; it also indicates the forms and customary courtesies to be observed in all international acts. "It is," says M. PradierFodere, "the code of international politeness." See P. Pradier-Fodere, Cours de droit diplomatique (Paris, 1899), ii. 499.
