Sure telltales to tell a terrapin is a yellow-bellied and not a red-eared

I have a yellow bellied slider which I need to transport to another country. YBS are allowed into that country, but it’s red eared slider cousins are not.

Now my problem is that, when chipped, the vet wrote just "Trachemys scripta" in the certificate, didn’t bother specifying which kind of TS it was. (YBS are Trachemys scripta scripta, while red eared are Trachemys scripta elegans).

The list of forbidden species for that country clearly specifies that "Trachemys scripta elegans" are not to be allowed. My worry is that when I reach the border and present my certificate, they will just match the Trachemys scripta and don’t bother asking anything else, just euthanise my pet.

My turtle has the yellow belly with just two big dots on the top area, but it also has an orangish mark on the side of his head.

Is there any sure tell that will allow me to mark the turtle as not being a TSE?