MULTI_PROMPT_ROUTER_TEMPLATE design

Is there any background info on why the MULTI_PROMPT_ROUTER_TEMPLATE is designed the way it was?

I see the use of many markers like ‘<<’ and ‘{{’ without any clear info and what these represent

For example :

<< CANDIDATE PROMPTS >>
{destinations}

<< INPUT >>
{{input}}

<< OUTPUT (remember to include the ```json)>>"""
type or paste code here

I have not taken that course, but I’d guess the model was fine-tuned to recognize those delimiters.

But then Im guessing this is very specific to the foundational model and does not generalize to all models?

That would require studying a few other models.