In Samsung firmware nomenclature, these characters are critical for compatibility:
Ensure your Google Account is removed or "OEM Unlock" is on, or the phone will block the custom file. The Baseband version If you have access to a Windows PC for the flash tools In Samsung firmware nomenclature
If the "U" version of the file doesn't match your device (e.g., trying to use U1 on a U2 device), the phone will fail to boot. In Samsung firmware nomenclature
Ensures the PC recognizes the phone via USB. In Samsung firmware nomenclature