Do you mean you would never HAVE guessed? Also, there ARE tankers which transport gas as opposed to petroleum spirit. Calling it a gas tanker is patently incorrect.
I ordered some kidney supplements for my dog from Amazon. They sent them with DHL. I had a phone call from DHL to say that I needed an import licence. I told them to return the supplements to Amazon. I then emailed Amazon with this information and asked them to re-send them by air mail through the post. They arrived without problem. Amazon then refunded the import tax (which they charge in advance) as no tax was paid.