: The video codec used to compress the file, popular in the late 2000s and early 2010s for its compatibility with older hardware players.

: You can still find DVD/Blu-ray copies through international retailers specializing in Korean cinema.

: Indicates the source of the video was a commercial DVD, typically offering better quality than "CAM" or "TS" versions.

The film is a somber mystery based on the true story of the "Frog Boys"—a famous cold case in South Korea involving the disappearance and murder of five young boys in 1991.