Standard, Private standard, rule 

How do standards, private standards and rules differ? 

Standards are private and therefore essentially voluntary rules, recommendations or specifications drawn up by experts for almost all areas of modern economic life. They document the current state of the art and can be divided into two groups: certifiable standards for contractual and certification purposes, and non-certifiable standards such as guidelines. Standards of the International Organization for Standardization (ISO), the International Electrotechnical Commission (IEC) and the International Telecommunications Union (ITU) are documents that are developed in a participatory and consensual manner, the functioning of which is verified every five years. In contrast to «private» standards – often used synonymously – an ISO, IEC and ITU standard is developed with the involvement of all interested parties as far as possible. This is why it has a quasi-public character and is widely accepted. 

A «private» standard differs from a «public» standard. The private standard has a stronger technical connotation. It can be seen as a guideline, procedure or formula on how best to do something. In particular, it serves as a benchmark for uniform comparison. Private standards may relate to a variety of activities and subjects. In contrast to «public» standards, they are less often developed in a participatory and consensual manner and more often set and enforced by one or a few market-powerful actors. 

A rule is a regulation or a generally accepted procedure that states how something is to be done or how something is done «as a rule». «Public» standards and «private» standards are two different types of rules.