Further to this: https://doc.dynamicweb.com/forum?ThreadID=64164&PID=1605, it looks like you can check out to countries that are not supported. Here's how:
1. In the CC add a new address with a country that doesn't exist under Settings | Ecommerce | Internationalization | Countries and save your changes
2. Under Settings | Ecommerce | Orders | Validation Groups add a rule for the country and set it to Equals "DK" (provided that DK is a supported Ecom country)
3. Go through checkout while logged in. Your address displays as read-only but the country doesn't show up
4. Complete the order
Actual results
1. The order completes successfully and the country is the one from step 1
Expected results
1. You're blocked from checking out, stating that your country must be DK.
Bug? Or am I missing something?