A BNR file contains information about a banner that visually represents a game, or "channel," loaded in the Nintendo Wii menu. It stores various properties of the banner, which include the banner image appearance and the animation and sound effect associated with the banner when the channel is displayed and selected.

BNR files are not meant to be manually opened by Nintendo Wii users. Instead, they are referenced by the Wii when the channel content is loaded in the Wii. BNR files are typically located in Wii data .BIN files (content.bin files). Some Wii gamers in the Wii Homebrew community enjoy modifying games to add their own custom content. These gamers may modify BNR files along with other files to customize the appearance of the banner in the Wii console or a Wii emulator, such as Dolphin.