Question about Sony UBP-X500

According to the operating instructions (https://www.sony.com/electronic... P. 26):

"Region code (BD/DVD-VIDEO only) Your player has a region code printed on its back and will only play BD/DVD-VIDEOs marked with the same region code or".

Unfortunately...

I don't know, sorry, I don't have a US blueray.

What does this mean? I have no restriction so far.