This is perfectly legal. Employment is employment at will: employers, not employees, decide the terms and conditions of employment, and can decide when to reward, when to discipline and for what, and when to terminate (or demote, suspend, etc.) employees, and employees do not have any right to be made aware in advance of the policies or expectations to which they are held. Not to put too fine a point on it, but an employee at will has essentially no rights at work, other than--1) Not to be discriminated against or harassed due to a handful of protected characteristics, like race, national origin, sex, religion, age over 40, or disability; 2) To not be disciplined or fired in violation of a written employment contract, IF the employee has a written employment contract (if there is a contract, the employer must honor its terms). Other than that, since management can change policies at will or take action against employees for *any* reason, even ones not previously considered, it is perfectly legal to have "hidden policies" that only management is aware of.