At the moment players are only capable of adding notes to items and characters if they are added to the "Can Be Edited By" section by the GM and then writing into the same Public Description that the GM uses. I suggest implementing a 3rd category, alongside Public Notes and GM Notes, as Player Notes. Whenever a player is added to the "In Player's Journal" section they should be allowed to edit a different text field than the Public Description & Notes, that way players can add details they feel are important to NPCs, Handouts, and Items all while the GM's permanent public notes aren't affected.