I think the recient rash of pirate films have changed our opinions of 'The Bretherin of the Coast'. Most Pirates sailed without any Rules or Laws, thats why they were Pirates (look at BBC World Service News Reports about Somali Pirates nowerdays)!
Most Pirates agreed to certain rules within their crews, but as to with other Pirates I don't think so. One of the most lucrative acts of a pirate and or his crew ,was to turn 'Kings evidence' and to capture his fellow pirates and hand them over to any of the many Legal authorities. This made for less competition for them when they returned to their 'trade'.
Privateers however sailed with a 'Letter of Mark' from their backers, specifying, who, what, and when they could attack other vessels. Sir Henry Morgan was a Privateer and Blackbeard (William Teach) was a pirate. One ended up shot and beheaded the other Govenor of Jamaca! Guess which?