Maybe you've recently taken your Unmanned Aircraft Initial or Recurrent test, and received a score with some of those PLT codes on it (i.e. PLT530). What's next?
One great facet of the FAA is available information, free and easy. All of the codes are listed in one place: https://www.faa.gov/training_testing/testing/media/LearningStatementReferenceGuide.pdf. Each code has a knowledge area assignment. These aren't links that you can follow, but you can highlight the phrase, right-click and search it for specific knowledge.
Another source is Frequently Asked Questions. This site contains topical areas with links that you can follow by subject, not PLT code, but certainly great information. Hope this helps! And as always, our goal for you is
Safe flying! Thanks to Steve Desrosiers from Horizon Aviation for the information.