Background: Jackie Mason was born Yacov Moshe Maza in Sheboygan, Wisconsin, the fourth and last son (and first one born in the United States) in a family of six children in a strict Orthodox Jewish family. Mason came from a long line of rabbis, which included his father, his grandfather, his great-grandfather, and his great-great grandfather. His father Eli and his mother had both been born in Minsk, and had emigrated to the U.S. in the 1920s with the rest of Mason's family from Minsk; his father died in 1959. A Jewish refugee organization helped his father find a position in Sheboygan, as it needed a rabbi.
Context: On October 18, 1964, in an appearance on The Ed Sullivan Show, Mason allegedly gave host Ed Sullivan the finger on air. Footage of the incident shows Mason in the middle of doing his stand-up comedy act and then looking toward Sullivan, who had placed himself directly behind the camera, commenting that Sullivan was signaling him. Sullivan was reportedly letting Mason know (by holding up two fingers) that he had only two minutes left, and to cut his act short, as the program was about to cut away due to having been partly pre-empted by an impromptu speech by President Lyndon B. Johnson that the show carried. Mason--clearly distracted--began working his own fingers into his act to make fun of the situation, and pointed toward Sullivan with an index finger, a thumb, but not (as Sullivan mistakenly believed) his middle finger. Sullivan was clearly infuriated by this, and banned Mason from future appearances on the show, canceling Mason's $45,000 ($355,000 in current dollar terms), six-appearance contract. Mason denied knowingly giving Sullivan the middle finger; he later said that he had not heard of the middle finger gesture at that time. To clear his name, Mason filed a libel suit on the grounds that Sullivan had defamed him at the New York Supreme Court. That court dismissed most of Mason's complaint. Both Mason and Sullivan appealed to the New York Supreme Court Appellate Division (which reinstated three additional causes of action against Sullivan) in June 1966. He was nevertheless banned from the show for a period of time. Sullivan asserted that Mason was unpredictable and could not be trusted. Because of Sullivan's influence, he was branded as unreliable, volatile, and obscene, and he failed to get substantial TV work for the next two decades. There was no ruling on the merits, merely a determination that Mason's suit could proceed and that he would be given an opportunity to prove his claim. Mason was given a single comeback appearance on Sullivan's TV program two years later, and Sullivan publicly apologized to him, but the damage was done. At that time, Mason opened his monologue by saying, "It is a great thrill ... and a fantastic opportunity to see me in person again." Mason later appeared on the show five times: April 23, 1967; February 25, 1968; November 24, 1968; July 22, 1969; and August 31, 1969. Mason later said: "It took 20 years to overcome what happened in one minute". CANNOTANSWER
Question: What claim was this?

Answer:

To clear his name, Mason filed a libel suit on the grounds that Sullivan had defamed him at the New York Supreme Court.