The modern business is highly confidential. Companies have the deals which never become public, employee may have special conditions which no one knows about too.
This is just life and if you do not respect confidentiality you will have hard time finding people to do business with you or work for you. But what you can do is to treat your deals as public. What if your partners/employees/customers would know about the deal ? Would you be comfortable with it ? If you’re not the good chances are the deal is unfair and you should not get into it. I also try to apply the same principle to employees – OK their salaries are confidential but what if they would all know how much everybody earns and how the compensation is structured ? I would like to not to feel good about it.
Of course deal fairness and salaries is sensitive topics and if indeed everyone would know everbody’s terms and conditions some people would not be happy. Everyone has a different judgement – employees may have a different feeling about their performance compared to someone else and also customers and partners may have a similar feelings. Keeping everybody happy is impossible but making sure you feel good and fair about any deal is.