One of the biggest mistakes you can make in your career is not understanding that there are certain codes and rules to abide by in the workplace. If you’re not careful, you may even lose opportunities because others are put off by your lack of professionalism. Don’t Listen to Your Music Player in the Elevator. and don’t check your e-mail messages. “Wearing earplugs is like putting a Do Not Disturb sign on you”. It sends a message to colleagues that you want to be left alone, an unfriendly gesture at best. Elevators and hallways are prime spots for friendly, ...