The ISI mark is a standards-compliance mark for industrial products in India since 1955. The mark certifies that a product conforms to an Indian standard developed by the Bureau of Indian Standards, the national standards body of India. The BIS product certification scheme is essentially voluntary in nature and is largely based on ISO Guide 28, which provides general rules for third party certification system of determining conformity with product standards through initial testing and assessment of a factory quality management system and its acceptance followed by surveillance that takes into account the factory Quality management system and the testing of samples from the factory and the open market. All BIS certifications are carried out in accordance with Indian Standards, which are amenable to certification. A large number of operational elements of the BIS product certification scheme correspond with the requirements of ISO Guide 65. BIS has mandatory and voluntary products to be applied for ISI marking.