Series. Most of the materials in the Media Center / Justice Lending Library were classified by format of material, title, and serial number. For example, FS/FF-80 refers to a Film Strip (format) named Forecasting the Future (title) with the serial number 80. Formats include F (film), FS (film strip), G (game), K (kit), SL (slide), and C, P, and T (unidentified).