I would like to know also

I believe it is the following based on https://huggingface.co/OrionStarAI/OrionStar-Yi-34B-Chat/blob/main/generation_utils.py:

chat format:

single-turn: <|startoftext|>Human: Hello!\n\nAssistant: <|endoftext|>

multi-turn: <|startoftext|>Human: Hello!\n\nAssistant: <|endoftext|>Hi!<|endoftext|>Human: How are you?\n\nAssistant: <|endoftext|>target2<|endoftext|>