The keyword "DLC - Boomerang Fu - NSP - 2 DLCs - switchrom.io-.zip" refers to a specific package of DLC content for Boomerang Fu, available for download on the Nintendo Switch. This package, hosted on switchrom.io, includes two DLC packs, which add a wealth of new content to the game.
The DLC package, which can be downloaded as a .zip file from switchrom.io, includes the following content: DLC - Boomerang Fu -NSP--2 DLCs--switchrom.io-.zip