Generally standards are considered to be shorthand manuals that claim guidance on 'doing things' or 'making things'. Although the use of a standard is not legally imposed, manufacturers are encouraged to adhere to common methods or specifications to establish agreed norms between all interested parties (producers, distributors and consumers).
Consensus standards (those representing current best practice) are usually divided into three geographical levels and adopted by the equivalent official standardisation body (national - ASTM*, BS, DIN** etc, regional - EN and international - ISO). It is possible for a standard to be accepted on more than one geographical level and it is common to find standards agreed by the British Standards Institute (BS), the European Committee for Standardisation (EN) and the International Organisation of Standardisation (ISO). In these cases standards are referred to as follows: BS EN ISO (standard number) (year).
When working to standards it is extremely important to check that the current edition is being referred to as many are revised, reviewed and withdrawn. This can be done by referring back to the standardisation organisation and checking its status.