Do foreigners need a visa for Phu Quoc Island in Vietnam

I have read in some travel websites that foreigners can visit Phu Quoc Island in Vietnam without any visa required. Is it true and for which nationalities will this apply? Let's explain the rules and regulations for this special zone?

As I mentioned in Countries with broad visa-free entry, Phu Quoc Island, Vietnam has a visa exemption policy for international visitors for a temporary stays of up to 30 days.