A more thorough explanation:

Federal Reporter Third Series

The Federal Reporter Third Series is a legal reference book that contains published court opinions from the United States federal courts. It is commonly abbreviated as "f.3d."

An example of a citation in the Federal Reporter Third Series would be: Smith v. Jones, 123 F.3d 456 (5th Cir. 2001). This citation refers to a court case where Smith sued Jones in the United States Court of Appeals for the Fifth Circuit in 2001.

Another example would be: United States v. Johnson, 789 F.3d 123 (2d Cir. 2015). This citation refers to a court case where the United States government prosecuted Johnson in the United States Court of Appeals for the Second Circuit in 2015.

The Federal Reporter Third Series is a collection of published court opinions from the United States federal courts. These opinions are written by judges and provide legal precedent for future cases. The examples given show how a citation in the Federal Reporter Third Series is formatted and how it refers to a specific court case. This reference book is commonly used by lawyers, judges, and legal scholars to research and analyze legal issues.