Inspired by Unreal_Ed's other suggestions regarding Notebook usability, I think that there is some benefit in being able to allow some players read, but not write, to notebook pages.
I think it should be available in two places:
  • a pair of global Options -> Permissions checkmarks to allow all players read and/or write in notebook pages.
  • a pair of color swatches on each notebook page, for read permissions and for write permissions.

Use cases could include things like rules, which should be accessible to everyone but not easily modifiable, intentionally or accidentally, or manual logging of game events by a designated player so it's not as easy to tamper with.