ISO 80000 or IEC 80000 is an international standard promulgated jointly by the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC).
The standard introduces the International System of Quantities (ISQ). It is a style guide for the use of physical quantities and units of measurement, and formulas involving them, in scientific and educational documents for worldwide use. In most countries, the notations used in mathematics and science textbooks at schools and universities follow closely the guidelines in this standard.
The ISO/IEC 80000 family of standards was completed with the publication of Part 1 in November 2009.
Parts
The standard has 14 parts:
International System of Quantities
Part 1 of ISO/IEC 80000 introduces the International System of Quantities and describes its relationship with the International System of Units (SI). Specifically, its introduction states "The system of quantities, including the relations among the quantities used as the basis of the units of the SI, is named the International System of Quantities, denoted 'ISQ', in all languages.", and further clarifies that "ISQ is simply a convenient notation to assign to the essentially infinite and continually evolving and expanding system of quantities and equations on which all of modern science and technology rests".
Binary prefixes
A 1999 addendum to IEC 60027-2 on binary prefixes has resulted in public interest in the standard and is still being widely discussed in the computer community, as it provides a clear framework of prefixes that resolve the discrepancy and resulting confusion of using, e.g., a kilobit to indicate 1000 bits (1 kbit) or 1024 bits (1 Kibit).
The harmonized IEC 80000-13:2008 standard cancels and replaces subclauses 3.8 and 3.9 of IEC 60027-2:2005, those defining prefixes for binary multiples. The only significant change is the addition of explicit definitions for some quantities.