Copyright Office Fair Use Index. Fair use is a longstanding and vital aspect of American copyright law. The goal of the Index is to make the principles and application of fair use more accessible and understandable to the public by presenting a searchable database of court opinions, including by category and type of use (e.g., music, internet/digitization, parody).The Fair Use Index tracks a variety of judicial decisions to help both lawyers and nonlawyers better understand the types of uses courts have previously determined to be fair or not fair. The decisions span multiple federal jurisdictions, including the U.S. Supreme Court, circuit courts of appeal, and district courts. Please note that while the Index incorporates a broad selection