1. A standardized, conventional expression used in formal or official contexts, particularly in diplomatic, ceremonial, or administrative settings
The ambassador opened the speech with the customary formal phrases.
A embaixadora abriu o discurso com as frases protocolares usuais.
2. A ritualistic or ceremonial utterance that follows established convention
He used protocol phrases to maintain diplomatic decorum.
Ele usou frases protocolares para manter o decoro diplomático.