A job at Goldman Sachs is an enviable position - just make sure you never send the phrase "I am not a happy camper" using your work e-mail address.

A document obtained by CNBC has revealed the strict e-mail protocol at work within the investment bank, with an automatic moderating surveillance system flagging mails that contains unaccepted phrases, such as profanities, signs of insider trading, disputes or sometimes simple misunderstandings.

The flagged emails are later reviewed by human employees, deciding if they are problematic or not. Any sign of illegalities or insider trading are taken into further investigation.

Some of the unaccepted phrases contain profanities, which are not often accepted in work places. Phrases like: "don't you f—ing understand," "mad/angry/frustrated as hell/f---," "Screw/f--- it up," "way too f---ing much," "what I f---ing said," "where the f---/hell are you," "who the heck/f---/hell do you think you are," and "don't you f---ing understand" made the list.

However, Goldman Sachs takes the moderating a step further. The system looks for seemingly innocent phrases, such as: “I am not a happy camper”, “I trusted/believed in/had faith in you” and even “I don’t/dont/do not understand”.

"We deploy cutting-edge technology and exercise the utmost care to protect confidential information, secure data and provide high-end client service. The firm's monitoring efforts reflect our commitment to upholding the highest standards of professionalism and integrity," spokesperson of Goldman Sachs told CNBC.

The full list of the flagged sentences can be found here.