Protocol is derived from the Greek proto kollen, or "first glue," and in its earliest English form referred to a sheet of paper glued to the front of a notarized document as verification of its authenticity. In its official sense, it has come to refer to a system of universally accepted etiquette used when representatives of different nations deal with one another. It also applies to official dealings on the national, state, and local levels.
Protocol is the glue that holds official life together—the observance of precedence and rank in such aspects of official life as using proper forms of address, participating in ceremonies, and entertaining dignitaries.
Many of these "official" manners are observed by ordinary citizens on occasion. View our Official Forms of Address articles for more information.