What exactly do moderators want to see in the Additional Notes area of a game request? It says "proposed categories, rules, your plans for the board, etc," but should you also include a short description of the game, or anything else relating to it? Should you elaborate on almost everything, or keep the notes short and sweet?
Usually you can keep it empty. If the game is pretty straightforward, you can get away with not including any details. If the game is confusing to an outside viewer on what the category's end goal is, you could explain that in the notes. All in all, it's optional. You can be as descriptive as you want (or don't want).
Would like to add from my own experience that if the game you're submitting fundamentally breaches the rules for adding a board on the site, regardless of the description it will be rejected. If you think it might appear to conflict with one rule it could help to explain why it doesn't (in your opinion).