The kashrut authorities have found an interesting loophole. It’s a violation of the first amendment for a state to directly ban the labeling of unkosher food as

The kashrut authorities have found an interesting loophole. It’s a violation of the first amendment for a state to directly ban the labeling of unkosher food as kosher. Too much entanglement with religion. However the various authorities have registered trademarks like ou and k. Enforcing ordinary trademark law runs into no constitutional issues.