Identify the "Rules for Ghosts" in Act 1 of Hamlet?

Okay so I just finished reading the first Act of Hamlet and I have this question for homework. I understand what happened but Im confused with what this means. Would the answer be "The ghost tells Hamlet the secret of his father's death. Hamlet's father was not killed by a serpent, but was murdered with poison. He also told hamlet that it was his uncle who murdered his father, and that he also seduced Gertrude, his mother. The ghost then tells Hamlet to avenge his father's death but to leave his mother alone" ?