De facto standard

A de facto standard is a custom, convention, product, or system that has achieved a dominant position by public acceptance or market forces (such as early entrance to the market). De facto is a Latin expression that means "by fact". In law, it means "in practice but not necessarily ordained by law" or "in practice or actuality, but without being officially established". It is commonly used in contrast to de jure (which means "concerning the law") when referring to matters of law, governance, or technique (such as standards) that are found in the common experience. When discussing a legal situation, de jure designates what the law says, while de facto designates action of what happens in practice. The term de facto may also be used when there is no relevant law or standard, but a common and well established practice that is considered the accepted norm. Other standards may be voluntary or may be de jure ("ordained by law") standards enforced by government.

In contrast, a technical standard is an established norm or requirement. It is usually a formal document that establishes uniform engineering or technical criteria, methods, processes and practices.

In social sciences, a de facto standard is a usual solution to a coordination problem. The choice of a de facto standard is the better choice for situations in which all parties can realize mutual gains, but only by making mutually consistent decisions.

Examples:

- The QWERTY system was one of several options for the layout of letters on typewriter (and later keyboard) keys. It became a de facto standard because it was used on the most commercially successful early typewriters, and once people had learned the QWERTY layout they did not want to re-learn a different system.

- When the VHS format for videotape recording was introduced, other recording formats were already available in the market. Regardless of whether Betamax was superior from a technical point of view or not, the VHS format won the format war due to superior marketing tactics by its proponents. The market could not support two competing formats; VHS became the de facto standard and Betamax was eventually withdrawn.

- The driver's seat side in a country.

- The use of the AA battery (as opposed to AAA or other previously proposed standards for low-voltage and small-size batteries).

- Computer file formats:

1) AutoCAD DXF: a de facto ASCII format for import/export of CAD drawings and fragments in the 1980s and 1990s. In the 2000s, XML standards such as SVG emerged as de facto standards.

2) Microsoft Word DOC: one of the best known de facto standards. Due to the market dominance of Word, it is supported by all office applications that intend to compete with it, typically by reverse engineering the undocumented file format. Microsoft has repeatedly internally changed the file specification between versions of Word to suit their own needs, while continuing to reuse the same file extension identifier for different versions.

3) HTML is a good example of "de facto and de jure" standard.

4) MP3: a non-free audio format now supported by almost all music players

5) The IBM Personal Computer format, which used MS-DOS and Microsoft Windows operating systems, gained a large share of the personal computer market. Competing products like the Rainbow 100 were eventually withdrawn and others.