1. Never tell your boss your detailed financial situation.
2. Do not tell your boss your career plans beyond your current job, apart from conversations about possible internal moves that your boss supports.
3. Don’t pass on negative things you have heard about your manager, or gossip in general.
4. Don’t tell your manager about aspirations that are likely to evoke a fear reaction.
5. Never tell your boss about crises in your personal life unless they intersect with your work.
6. Do not criticize your co-workers to your boss.
7. Don’t tell your manager that you are so unhappy in your job you’re ready to quit, unless you are ready to walk out then and there.
8. Don’t tell your boss anything a colleague has told you in confidence, unless it is a matter of grave significance that a manager needs to act on.
9. Finally, never tell your boss anything that your boss could use against you.