One of the world's most famous merchant captains died, having long been admired by his crew and fellow officers. They were puzzled, however, over a strange ritual he performed daily while at sea. He would lock himself in his cabin, open a small safe, take out an envelope, and read the note inside. After returning the note to its place in the safe, he would resume his duties.
For years this went on, and his crew became very curious. Was it a treasure map? Was it a letter from a long lost love? Everyone speculated about the contents of the strange envelope. After laying the captain's body to rest, the first mate led the crew back to the ship and into the captain's quarters. He opened the safe, got the envelope, and read the note aloud to the astonished crew:
"Port: Left, Starboard: Right."