Possible Clues:

• International action, such as may set a precedent?
• Legal precedent created by playing cassette
• Representative legal action likely to become a precedent
• Cassette unravelled in ground­breaking action
• Cassette produced for the judge to hear setting a potential precedent
• Precedent, maybe
• Source of a legal precedent
• Precedent setter in court
• Precedent (lawsuit)
• Taste sec blends -- sip from a dozen bottles as trial run?