the.com/protocol

means An agreed set of rules or steps — for a negotiation, a computer network, or a ceremony — that everyone follows so things go in the expected order.

from From Greek 'protokollon' — 'proto' (first) plus 'kollon' (glue). Literally the first sheet glued to the front of a papyrus scroll, stating what was inside and authenticating it. The word drifted from 'the official cover page' to 'the official procedure' as diplomats used it for the agreed record of a negotiation, and later for any formally fixed set of steps — including, much later, the rules computers use to talk to each other.