The lesson planner, quarterly planner and semester planner have 5 AND 6 columns. The 6th column can be used for notes, Saturday, or grades.
Goals/Objectives
The Objectives planner can be used to take notes of specific things that your child needs to work on. Keep these in your planner and review them every six weeks more or less. The Goals planner can be used as part of creating custom curriculum or to take note of broad goals that you have for your child for that school year or for a shorter span of time.
Book Key
The book key is described on the original book key web page. I designed the book key to simplify recording lesson plans in the planners. I even put small stickers on my book spines and wrote the book keys on the stickers. I stopped using stickers after a couple of years.
Checklist
The checklist is described on the original checklist web page. I designed the checklist to simplify using a subject planner notebook. My children appreciated the checklist. Using it gave them the a first taste of time management. They could see that soon, they would be finished with their daily work.