Other ISO 9660 CD-ROM filesystem on USB stick

I have a USB stick which has an ISO 9660 CD-ROM filesystem according to file -s /dev/da0.

After gpart destroy -F da0 and gpart create -s GPT da0 there are no partitions but file -s /dev/da0 continues to report the same.

Where does this information come from?
Do what?
Destroy then create and you wonder why file -s shows structure?

How about create then destroy and do file -s

/dev will not show empty schemes only partitions.
I should clarify. /dev won't show empty disk schemes but labels can be involved if you use them and they reside in /dev too.

I always disable them by default. When debugging they can really disrupt.