Under Title VII of the Civil Rights Act, employees can take employers to court for discrimination based on race, color, religion, sex or national origin. But the law requires that an employee first file a charge with the federal Equal Employment Opportunity Commission within 180 days of the supposed violation (300 days if a state or local agency is investigating under state or local law).
Only after receiving EEOC clearance can an employee sue the employer in federal court. If an employee sues without EEOC clearance, the employer can get the lawsuit dismissed. But as the U.S. Supreme Court decided this spring, you must do that quickly or you forfeit that right forever.
In the case, the plaintiff had already filed a sexual harassment charge with the EEOC when she was fired for refusing to work on Sundays for religious reasons. She tried to add religious discrimination to her charge by handwriting it on an intake questionnaire, but she made no formal change to her charge. She then sued the employer in federal court after getting clearance from the EEOC.
Several years later, the religious discrimination claim was the only one that had not been resolved. At that point the employer tried to get it thrown out by pointing out that the employee had never formally raised the charge with the EEOC.
A U.S. District Court judge agreed, but the Supreme Court reversed the decision and ordered the claim reinstated, ruling that the charge-filing requirement is just a processing requirement and did not strip the federal court of the ability to hear the claim after the employer failed to act quickly.