Complex sentence: Sailors who are plank owners at their current command often have the word "PLANKOWNER" embroidered on the back of their uniform ball cap to denote this designation and a plaque is placed aboard the ship with the crew names.
Split into simpler sentences: Sailors who are plank owners at their current command often have the word "PLANKOWNER" embroidered on the back of their uniform ball cap to denote this designation. A plaque is placed aboard the ship with the crew names.