How was NBC able to broadcast Schindler's List uninterrupted in 1997?

I just learned that on February 23, 1997, NBC aired the Holocaust movie *Schindler's List*, uncut and without commercial interruptions (though sponsored by Ford Motor Company). I thought American TV networks were required to do station identification once per hour, so this seems like it would have broken the law. Did they get special permission from the FCC? Is the "requirement" not actually a requirement? Did they in fact interrupt the movie for station ID but not commercials? Was it plain against the law, but Ford Motor Company covered whatever FCC fine NBC would have gotten? Has anything like this happened before or since?