Unwritten rules in organizations

Have you ever worked for an organization that had expectations of you that were unspoken? That is, you got the impression that if you didn't do what they were asking of you that you would be fired.

Here is an example from an organization that required "obligatory overtime." The folks at Slow Leadership lay out the story fairly well and correctly call it 'Management Double-Speak.' It is well worth the time to read.

Can you think of other examples, besides the 'obligatory overtime,' that management has required of you or others? What are other legal and ethical issues relating to the employer/employee relationship that you've had to deal with in the past?