I also strongly request this feature. For business it is essential as during the day we may have different note taking information in different note taking penultimate notebooks (e.g. meetings, notes, activity lists, week, monthly plans....) that will be later organized and tagged into different topics. Just to put an example: A back to back meeting day: I have a penultimate meeting notes notebook that I use to keep track and record the minutes of my meetings. One my day is over, during my daily review I would like to attach those meeting notes and minutes to the notebooks (i.e. work projects) they are related to with corresponding tags if they need to be sorted by priority, etc.... I am keeping all my notes together as I really hope you guys can do it!!!! Thanks!!!!