Files with the USFLIB extension are mainly associated with the older Nintendo 64 game console. USFLIB files are used to store a library of songs most often used in a specific game. The list created in this way refers to the actual audio files to be played and gives them the MINIUSF extension.

The condition for the correct playback of the tracks from the MINIUSF files USFLIB list is that all these files must be in the same location, including the USFLIB file.