CITES spieces are one that are endangered. For them you need to have special papers that shows they are legally obtained. Most popular CITES spieces are all crcodoiles, pythons, elephant, hipo and some spieces of lizards(fe. waranus niloctus). I've got them with papers valid within EU, when importing you need to get CITES import permit - it's possible with my papers but it takes approx 3 months to get this permit. But I won't even offer you those spieces, as I prefer to deal with them only within EU. On my site every spiece that need CITES got this info in details.
And for raw leather it's leather that haven't been tanned, due to health care it need to have lots of work done before importing. Same goes for bones, antlers, teeth etc.
Sharks, stingrays, eel and most of snakes are non-CITES spieces, so no paperwork need to be done - it's just like cow leather.