A usf file extension is related to the Nintendo Ultra 64 sound format. Probably obsolete format.
There is one other file type using
the USF file extension!
.usf - Core Media Player XML universal subtitle format
USF file extension - Nintendo Ultra 64 sound format
What is usf file? How to open usf files?
File type specification:
The usf file extension is also used for an audio format used on Nintendo Ultra 64 consoles.
USF is a file format which contains all the data needed to play a song from an N64 game. Once the song has been ripped into a USF file you can load it up in a player and listen to the music.
This usf file type entry was marked as obsolete and no longer supported file format.
This type of file is no longer actively used and is most likely obsolete. This is typically the case for system files in old operating systems, file types from long discontinued software, or previous versions of certain file types (like documents, projects etc.) that were replaced in higher versions of their original programs.