Someone in your respective NN may have explained this already but I’ll see if I can’t explain it better.

To alter your chat logs, go to Menu -> Character Configuration -> Log Window Settings (at the very bottom) -> Log Filters (also at the very bottom.) These four logs numbered 1 through 4 are your respective chats, the first three should be, “General”, “Battle”, and “Event”, with the 4th being a optional one for anything you want.

You can edit these logs by clicking on them, and customize them to your liking with what you want to show in them, for example, you could filter out the NN from the first three but make a specific chat dedicated to the NN in the 4th slot. You can also alter the size of the log window by clicking on the top right of it and dragging your cursor.