Simplify the following text for a Grade 9 native English-speaking person.
Original: In the second half of the 17th century , buccaneers began operating under a set of rules variously called the Chasse-Partie , Charter Party , Custom of the Coast , or Jamaica Discipline .
Simplified: In the second half of the 17th century , buccaneers started following rules . These rules had many different names , including Chasse-Partie , Charter Party , Custom of the Coast , or Jamaica Discipline .