Some companies provide a Code of Conduct for their employees to promote professional behaviour. 

These are non-legally binding rules which the company expects their employees to abide by. The employee will need to agree to these when first employed.

If an employee breaks these rules, he/she may be asked to leave the company.

It is always in the best interest of a business to treat its customers fairly and with due consideration - or they will go elsewhere.

It ensures consistency of practice. All employees would conduct their business in a similar way.

They are sometimes called Codes of Practice.

Here is one issued by a school for its pupils: