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 (IS) developed by the Bureau of Indian Standards (BIS), the national standards body of India. The ISI mark is by far the most recognized certification mark in the Indian subcontinent. The ISI is an initialism of Indian Standards Institution, the name of the national standards body until 1 January 1987, when it was renamed to the Bureau of Indian Standards. The ISI mark is mandatory for certain products to be sold in India, such as many electrical appliances like switches, electric motors, wiring cables, heaters, kitchen appliances, etc., and other products like Portland cement, LPG valves, LPG cylinders, automotive tyres, etc. In the case of most other products, ISI marks are optional.