protocol

First recorded in 1535–45; earlier protocoll, from Medieval Latin prōtocollum, from Late Greek prōtókollon originally, “a leaf or tag attached to a rolled papyrus manuscript and containing notes as to contents.” See proto-, colloid

Protocol ultimately comes from Late Greek prōtókollon, a compound noun meaning “the first kóllēma (sheet) on a papyrus roll,” formed from prōto-, a combining form of prôtos “first” (and completely naturalized in English) and the noun kóllēma “something bound or glued together” (the plural kollēmata means “sheets of papyrus glued together to form a roll,” usually 20 sheets, averaging 20–26 feet in length). Prōtókollon is first recorded in the Novels, one of the four divisions of the Corpus Juris Civilis, compiled by order of the emperor Justinian (a.d. 483–565), the last native Latin-speaking emperor. A prōtókollon protected the outside of a rolled-up scroll (and therefore was sometimes reinforced with parchment). The protocol was the equivalent of the modern copyright page and table of contents, bearing official authentication, date of manufacture, author, and contents.
In Medieval Latin prōtocollum acquired the meaning “draft (of a document), minutes (of a meeting), public register, a document bearing an official seal.” By the middle of the 19th century, French developed the sense “official norms of behavior or etiquette to be maintained between states and their ministers; the accepted and customary codes of behavior in polite society.” In late 19th-century Russia, protocol ( protokól ) meant “an official police record of a case or incident,” its meaning in the infamous “Protocols [ protokóly ] of the Elders of Zion,” first published in Russia in 1903.

C16: from Medieval Latin prōtocollum, from Late Greek prōtokollon sheet glued to the front of a manuscript, from proto- + kolla glue