The Declaration of Paris codified the rules for naval engagements involving civilian vessels. The so-called Cruiser Rules required that the crew and passengers of civilian ships be safeguarded in the event that the ship is to be confiscated or sunk. These rules also placed some onus on the ship itself, in that the merchant ship had to be flying its own flag, and not pretending to be of a different nationality. Also, it had to stop when confronted and allow itself to be boarded and searched, and it was not allowed to be armed or to take any hostile or evasive actions. When war was declared, British merchant ships were given orders to ram submarines that surfaced to issue the warnings required by the Cruiser Rules.