Thanks to everybody answered. Cornelius, my question was provoked by one of the questions from the PMP Exam simulator. When a PM was advised to cut out the sensitive information from the Stakeholder Register. I answered that she shouldn't cut it out. Because of Code of Ethics. No lie!

And it was the wrong answer.

And then I decided to ask the people's opinion here. So, it is about exam, but for understanding the topic better. I might have skipped something in PMBOK, saying what to do in these cases.
OK, I see different opinions. I have taken into account the security issues. Thank you, all!