I think we need another dimension: time
I mean, if something already occured, it can´t be modified, except by the Alpha Story guide. Than, even the owner of an object should not edited parts that are connected with events already played.
Of course there are items that do not need this dimension, and others will allow only additions, not modifications ...

I wonder because there might be multiple degrees of protection, so to speak. A group might know one thing about a character, and another group might know a different thing about the same character.