Is it possible to make notes on the board that only the creator can see? 

Thank you for your answer and suggestion Robert, much appreciated.

​This suggestion is a good idea for “nuclear strength” privacy. Another idea that I use is simply to put anything secret onto a frame, then hide the frame. As the owner of the board I am the only one to be able to unhide the frame. Naturally if I unhide it other people will see it when it is unhidden, so that’s a disadvantage.

I also have never used Notes myself, but maybe that is an option?  I suspect “hide authorship” may be just that, hiding who created the note not hiding the note itself. So it could work well if you could develop your own secret language then not share it with anyone. 😉

Great shoutout ​@Kenneth Ritley with the Frames hide/reveal! The downside, as you mentioned can be that an unhidden frame can be viewed by anyone also on the board at the same time the frame is unhidden. To read more about the hide/reveal frames feature ​@Kenneth Ritley is referring to here:

https://help.miro.com/hc/en-us/articles/360018261813-Frames#01H7YR4H1CWPG1PH1N2AT3ZXAP

Re the Visual notes authorship, it’s as Ken suspected — it simply shows who typed what:

Click the Show authorship icon to see the initials of content creators to make it easier for other contributors to determine who is responsible for changes and additions to the note.