(VOVworld) - The United States Patent and Trademark Office has granted a patent to Nang Thom Cho Dao rice and Chau Thanh dragon fruit, which are special foods of Long An province. The certification is valid for ten years and can be extended several times. The trademark protection certificates will ensure three rights for their holders. They will prohibit any production units with the same business line in the country using the trademark; confer the right to transfer the trademark to any partner in the country; and confer the right to request law enforcement agencies to protect the trademark against violators.