In the context of USBUtil, "USB Mode 2" typically refers to the compatibility settings within the software that ensure the generated files are optimized for the PS2's specific read requirements. While older versions of OPL required specific folder structures, USBUtil simplifies the process by placing all necessary components directly onto the drive's root.

The "V2.1" designation refers to the version number, which brought significant stability improvements and bug fixes over earlier iterations, making it the standard for years.