JIS drivers work extremely well to break frozen Phillips screws. I've also used JIS screwdrivers to fix partially stripped Phillips screws: Tap on the stripped screws with a JIS screwdriver and hammer to reform the head, then turn. Or even better, use an impact JIS driver. Saved my skin many times on my motorcycles. https://www.amazon.com/Vessel-125943-P3x150-Impacta-Screwdri...

Does it have another cross lightly engraved on the head, 45 degrees off from the main cross? Then it's Pozidriv. Does it have a small circular dot in one corner of the head? Then it's JIS.

There may be the occasional unmarked JIS screw though.