Technical standard
A technical standard is an established norm or requirement in regard to technical systems.
Description
It is usually a formal document that establishes uniform engineering or technical criteria, methods, processes and practices.
In contrast, a custom, convention, company product, corporate standard, etc. that becomes generally accepted and dominant is often called a de facto standard.
A technical standard may be developed privately or unilaterally, for example by a corporation, regulatory body, military, etc.
Standards can also be developed by groups such as trade unions, and trade associations.
Standards organizations often have more diverse input and usually develop voluntary standards: these might become mandatory if adopted by a government, business contract, etc.