Established criteria against which performance can be measured. They might take the form of a technical specification for a product, for example, or a code of practice for a service business, that is recognised and used as rule or guide to follow within a particular business or industry, and may be recognised on a national, European or international basis. Nationally, European and internationally recognised standards are developed and established through a period of public enquiry and full consultation. They incorporate the views and expert opinions of a very wide range of interest groups including those of consumers, business and industry leaders, the government and special interest groups. Hence, such standards represent a consensus on current best practice. Standards are essentially designed for voluntary use and do not impose any regulations. However, laws and regulations may refer to certain standards and make compliance with them compulsory. See quality standards, BSI, BS5750, En 2000 ISO 9000.