Grice's Maxims (1975)
Maxim of Quantity - Do not say too much or too little in a conversation.
Maxim of Quality - Be truthful when speaking.
Maxim of Relevance - Keep to the point and to not evade the question.
Maxim of Manner - Speak in a clear and orderly way.
Shlegoff's canonical sequence (1986)
1) Summons/ answer. - opens the channel of communication.
2) Identification/ recognition. - not needed for Face-to-face.
3) Greetings sequence.