The question then would be whether to train it to respond to short prompts with longer correspondence style "letters" or to leave it up to the user to write a proper letter as a prompt. Now that would be amusing
Dear Hon. Historical LLM
I hope this letter finds you well. It is with no small urgency that I write to you seeking assistance, believing such an erudite and learned fellow as yourself should be the best one to furnish me with an answer to such a vexing question as this which I now pose to you. Pray tell, what is the capital of France?