The U.S. Supreme Court has just handed employers one more reason to keep quiet when asked to give a job reference for a former employee. Charles Robinson sued Shell Oil Co. for race discrimination after he was fired. Later, when Shell gave him a negative reference, he filed a second lawsuit charging that the bad reference was illegal retaliation for filing the original discrimination suit. Shell contended that the federal job bias law, which bans retaliation against employees who make complaints, doesn’t apply to former workers. But the high court disagreed and let Robinson’s case go forward.8 In light of this decision, it’s critical to avoid giving a negative reference, or taking any other action that could be viewed as retaliation, against a current-or former-employee who has made a discrimination complaint against you. In fact, although the court didn’t address this point, to be absolutely safe, it’s best not to even mention to prospective employers that an ex-employee has filed such a claim.