Editing Binary prefix (section)

=== IEC 1999 Standard ===
In 1995, the [[International Union of Pure and Applied Chemistry]]'s (IUPAC) Interdivisional Committee on Nomenclature and Symbols (IDCNS) proposed the prefixes "kibi" (short for "kilobinary"), "mebi" ("megabinary"), "gibi" ("gigabinary") and "tebi" ("terabinary"), with respective symbols "kb", "Mb", "Gb" and "Tb",<ref name="iucr1995" /> for binary multipliers. The proposal suggested that the SI prefixes should be used only for powers of 10; so that a disk drive capacity of "500 gigabytes", "0.5 terabytes", "500&nbsp;GB", or "0.5&nbsp;TB" should all mean {{val|500|e=9|u=bytes}}, exactly or approximately, rather than {{nowrap|500 × 2<sup>30</sup>}} (=&nbsp;{{val|536870912000}}) or {{nowrap|0.5 × 2<sup>40</sup>}} (=&nbsp;{{val|549755813888}}).

The proposal was not accepted by IUPAC at the time, but was taken up in 1996 by the [[Institute of Electrical and Electronics Engineers]] (IEEE) in collaboration with the [[International Organization for Standardization]] (ISO) and [[International Electrotechnical Commission]] (IEC). The prefixes "kibi", "mebi", "gibi" and "tebi" were retained, but with the symbols "Ki" (with capital "K"), "Mi", "Gi" and "Ti" respectively.<ref name="iucr1996" /><!-- The preceding reference is weak as it merely consists of IUPAC noting IEC's proposal, but it is apparently the only thing we have. Would be better to have a ref for the actual proposal -->

In January 1999, the IEC published this proposal, with additional prefixes "pebi" ("Pi") and "exbi" ("Ei"), as an international standard ([[IEC 60027-2]] Amendment 2)<ref name="iec1999" /><!--- the preceding reference really needs more than just a quote. From what is it quoting? ---><ref name="iucr1999" /><!--- this reference is weak as it merely consists of the International Union of Crystallography reporting on IUPAC's reporting on the IEC standard(!) ---><ref name="IEC2000" /> The standard reaffirmed the BIPM's position that the SI prefixes should always denote powers of 10. The third edition of the standard, published in 2005, added prefixes "zebi" and "yobi", thus matching all then-defined SI prefixes with binary counterparts.<ref name="iec2005" />

The harmonized [[International Organization for Standardization|ISO]]/[[International Electrotechnical Commission|IEC]] [[IEC 80000-13]]:2025 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.<ref name="niso2008" /><!--- once again, a link to a cite to the document, not to the actual ISO/IEC document. This is unavoidable as the documents in question are *not* freely available ---> In 2009, the prefixes kibi-, mebi-, etc. were defined by [[ISO 80000-1]] in their own right, independently of the kibibyte, mebibyte, and so on.

The BIPM standard JCGM 200:2012 "International vocabulary of metrology – Basic and general concepts and associated terms (VIM), 3rd edition" lists the IEC binary prefixes and states "SI prefixes refer strictly to powers of 10, and should not be used for powers of 2. For example, 1 kilobit should not be used to represent {{val|1024}} bits (2<sup>10</sup>&nbsp;bits), which is 1 kibibit."<ref name="jcgm2012" />

The IEC 60027-2 standard recommended operating systems and other software were updated to use binary or decimal prefixes consistently, but incorrect usage of SI prefixes for binary multiples is still common. At the time, the IEEE decided that their standards would use the prefixes "kilo", etc. with their metric definitions, but allowed the binary definitions to be used in an interim period as long as such usage was explicitly pointed out on a case-by-case basis.<ref name="barr1997" />

==== Other standards bodies and organizations ====
The IEC standard binary prefixes are supported by other standardization bodies and technical organizations.

The United States [[National Institute of Standards and Technology]] (NIST) supports the ISO/IEC standards for
"Prefixes for binary multiples" and has a web page<ref name="NISTbin" /> documenting them, describing and justifying their use. NIST suggests that in English, the first syllable of the name of the binary-multiple prefix should be pronounced in the same way as the first syllable of the name of the corresponding SI prefix, and that the second syllable should be pronounced as ''bee''.<ref name="NIST2" /> NIST has stated the SI prefixes "refer strictly to powers of 10" and that the binary definitions "should not be used" for them.<ref name="taylo2008" />

As of 2014, the microelectronics industry standards body [[JEDEC]] describes the IEC prefixes in its online dictionary, but acknowledges that the SI prefixes and the symbols "K", "M" and "G" are still commonly used with the binary sense for memory sizes.<ref name="jedec2021" /><ref name="JEDEC2014" />

On 19 March 2005, the IEEE standard [[IEEE 1541-2002]] ("Prefixes for Binary Multiples") was elevated to a full-use standard by the IEEE Standards Association after a two-year trial period.<ref name="IEEE2003" /><ref name="IEEE2005" /> {{As of|2008|4|lc=on}}, the IEEE Publications division does not require the use of IEC prefixes in its major magazines such as ''Spectrum''<ref name="walli2008" /> or ''Computer''.<ref name ="gesch2007">{{Cite journal |last1=Gschwind |first1=Michael |title=An Open Source Environment for Cell Broadband Engine System Software |journal=Computer |volume=40 |issue=6 |pages=37–47 |publisher=IEEE Computer Society |date=June 2007 |doi = 10.1109/MC.2007.192 |last2=Erb |first2=David |last3=Manning |first3=Sid |last4=Nutter |first4=Mark |s2cid=10877922 |url=http://www.research.ibm.com/people/m/mikeg/papers/2007_ieeecomputer.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://www.research.ibm.com/people/m/mikeg/papers/2007_ieeecomputer.pdf |archive-date=2022-10-09 |url-status=live }} "The processor has a memory subsystem with separate first-level 32-Kbyte instruction and data caches, and a 512-Kbyte unified second-level cache." Authors are with IBM.</ref> <!-- and many of the IEEE technical journals allow the authors to select the units in their papers.{{Citation needed|date=May 2008}}-->

The [[International Bureau of Weights and Measures]] (BIPM), which maintains the [[International System of Units]] (SI), expressly prohibits the use of SI prefixes to denote binary multiples, and recommends the use of the IEC prefixes as an alternative since units of information are not included in the SI.<ref name="BIPM8web" /><ref name="BIPM8" />

The [[SAE International|Society of Automotive Engineers]] (SAE) prohibits the use of SI prefixes with anything but a power-of-1000 meaning, but does not cite the IEC binary prefixes.<ref name="SAE2017" />

The European Committee for Electrotechnical Standardization ([[CENELEC]]) adopted the IEC-recommended binary prefixes via the harmonization document HD&nbsp;60027-2:2003-03.<ref name="CENELEC2003" /> The European Union (EU) has required the use of the IEC binary prefixes since 2007.<ref name="CENELECxxxx" />