A plat is a plan, map, or chart of a piece of land with actual or proposed features; also the land which it represents. These have been collected in the Plat Books. Most of the Plats did seem to have a roughly drawn chart, and most of those that I have read had very long preambles about King Charles. They dated from 1672 to 1719. At that time England was trying to persuade people to colonize Jamaica.