In the past due to the communication lag the hostilities could proceed long after peace agreements were signed. This was especially severe for the overseas territories and ships. I'm somewhat more interested in how it was handled by navies.
It's quite obvious what happened when both parties were aware of the latest news on the international relations. It's also easy to imagine what would happen if one party was aware of the declaration of war whereas the other was not. However it's not really obvious what would happen when one party was aware of the peace agreement whereas the other was not because of the risk of deception.
My question is: What were the regulations in the Western navies of the 18th and 19th century for the situation when the enemy somehow communicated the claim that peace or ceasefire agreement was signed?
Note that I'm not asking what was possible and reasonable to do in that situation, rather what the commanding officer was expected to do according to the regulations so that his actions would be considered neither a violation of his duty with risk of being court-martialed nor a breach of freshly signed peace.