Never whisper to a particular person while in a group of three. It is very unethical. The third person would be hurt. If the number of people is four then it is OK.
Never get too friendly to someone from your professional background. Trust me, it could get very ugly one day. A competitor cannot be your true friend.
Never believe in rumor/what other says. Do thorough enquiry before believing whole-heartedly.
Do not argue with an ignorant/irrational people. It is impossible to win the argument with them. The moment you started arguing with them you have already lost.
Never hate people because of their appearance, caste, religion or sex. You never know who comes up in the time of your need.
Never say,“I will do this and this and this”. Instead, do it and then let your action tell,“You have done this and this and this”.
If someone asks you about something and you don’t know it or don’t like it then do not remain silent. It hurts the asker. Instead, reply politely that you do not know about it or do not feel like talking about it.
Never spit in front of someone. It is very unethical. It would hurt/offend them. If you really need to spit then move to a suitable place then spit.
Never be too available to everyone. You never know who would take wrong advantage out of this.
Never study or learn to pass the exam or to get a job. Instead, learn something to get the knowledge.
Never utter anything in anger. Pause for a moment, take a deep breath and then say whatever you want to.
Never consider some one incapable based on few parameters. He/she may possess something valuable that surpasses your all the abilities.
Never disrespect your parents no matter how illogical or unreasonable they may sound. Remember, you are here because of them; they are here not because of you.
Never make conclusion based on your assumption. It is also possible that your assumption is far distance from the reality.
Never struggle to make everyone happy. You cannot do it. It is beyond your limit.