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Micro (Greek letter μ, mu, non-italic) is a unit prefix in the metric system denoting a factor of 10⁻⁶ (one millionth).^[1] Confirmed in 1960, the prefix comes from the Greek μικρός (mikrós), meaning "small".

It is the only SI prefix which uses a character not from the Latin alphabet. In Unicode, the symbol is represented by U+03BC μ GREEK SMALL LETTER MU or the legacy symbol U+00B5 µ MICRO SIGN. The prefix "mc" is commonly used in healthcare or when the character "μ" is not available; for example, "mcg" commonly denotes a microgram.^[2] The letter "u" is sometimes used instead of "μ" when non-Latin characters are not available.

Examples

Typical bacteria are 1 to 10 micrometer (1–10 μm) in diameter.
Eukaryotic cells are typically 10 to 100 micrometers in diameter.^[3]

SI prefixes
v
t
e
Prefix		Base 10	Decimal	Adoption ^{[nb 1]}
Name	Symbol	Base 10	Decimal	Adoption ^{[nb 1]}
quetta	Q	10³⁰	1000000000000000000000000000000	2022^[4]
ronna	R	10²⁷	1000000000000000000000000000	2022^[4]
yotta	Y	10²⁴	1000000000000000000000000	1991
zetta	Z	10²¹	1000000000000000000000	1991
exa	E	10¹⁸	1000000000000000000	1975^[5]
peta	P	10¹⁵	1000000000000000	1975^[5]
tera	T	10¹²	1000000000000	1960
giga	G	10⁹	1000000000	1960
mega	M	10⁶	1000000	1873
kilo	k	10³	1000	1795
hecto	h	10²	100
deca	da	10¹	10
—	—	10⁰	1	—
deci	d	10⁻¹	0.1	1795
centi	c	10⁻²	0.01
milli	m	10⁻³	0.001
micro	μ	10⁻⁶	0.000001	1873
nano	n	10⁻⁹	0.000000001	1960
pico	p	10⁻¹²	0.000000000001	1960
femto	f	10⁻¹⁵	0.000000000000001	1964
atto	a	10⁻¹⁸	0.000000000000000001	1964
zepto	z	10⁻²¹	0.000000000000000000001	1991
yocto	y	10⁻²⁴	0.000000000000000000000001	1991
ronto	r	10⁻²⁷	0.000000000000000000000000001	2022^[4]
quecto	q	10⁻³⁰	0.000000000000000000000000000001	2022^[4]
Notes ^ Prefixes adopted before 1960 already existed before SI. The introduction of the CGS system was in 1873.

Symbol encoding in character sets

The official symbol for the SI prefix micro is a Greek lowercase mu (μ).^[6] For reasons stemming from its design, Unicode has two different character codes for the letter, with slightly different appearance in some fonts, although most fonts use the same glyph. U+00B5 µ MICRO SIGN (Alt+0181) is in the "Latin-1 Supplement" range identical to ISO/IEC 8859-1 (since 1987),^[7] residing at this code point also in DEC MCS (since 1983) and ECMA-94 (since 1985). U+03BC μ GREEK SMALL LETTER MU (Alt+956) is in the Greek range. According to The Unicode Consortium, the Greek letter character is preferred,^[8] but implementations must recognize the micro sign as well, for compatibility with legacy character sets. This distinction also occurs in some legacy code pages, notably Windows-1253.

In circumstances in which only the Latin alphabet is available, ISO 2955 (since 1974,^[9] withdrawn 2001^[10]), DIN 66030 (since 1980^[11]^[12]) and BS 6430 (since 1983) allow the prefix μ to be substituted by the letter u (or even U, if lowercase letters are not available), as, for example, in um for μm, or uF for μF, or in the common abbreviation UC for microcontroller (μC). Similarly, capacitor values according to the RKM code defined in IEC 60062 (since 1952) can be written as 4u7 (or 4U7) instead of 4μ7 if the Greek letter μ is not available.

The CJK Compatibility block contains square forms of some Japanese katakana measure and currency units. U+3343 ㍃ SQUARE MAIKURO corresponds to マイクロ maikuro.

Other abbreviating conventions

In some health care institutions, house rules deprecate the standard symbol for microgram, "μg", in prescribing or chart recording, because of the risk of giving an incorrect dose because of the misreading of poor handwriting.^[13] The two alternatives are to abbreviate as "mcg"^[13]^[2] or to write out "microgram" in full (see also List of abbreviations used in medical prescriptions). The alternative abbreviation may be ambiguous in rare circumstances in that mcg could also be read as a micrigram, i.e. 10⁻¹⁴ g; however the prefix micri is not standard, nor widely known, and is considered obsolete. This deprecation, focused on avoiding incorrect dosing in contexts where handwriting is often present, does not extend to all health-care contexts and institutions (for example, some clinical laboratories' reports adhere to it, whereas others do not^[13]), and in physical sciences research, "μg" remains the sole official abbreviation.

In medical data exchange according to the Health Level 7 (HL7) standard, the μ can be replaced by u as well.^[14]

References

^ International Bureau of Weights and Measures (2006), The International System of Units (SI) (PDF) (8th ed.), ISBN 92-822-2213-6, archived (PDF) from the original on 2021-06-04, retrieved 2021-12-16
^ ^a ^b "ISMP List of Error-Prone Abbreviations, Symbols, and Dose Designations: Abbreviations for Doses/Measurement Units". Recommendations. Institute for Safe Medication Practices (ISMP). 2021-02-05. Archived from the original on 2022-12-24. Retrieved 2022-12-24. Error-Prone Abbreviations, Symbols, and Dose Designations: μg […] Intended Meaning: Microgram […] Misinterpretation: Mistaken as mg […] Best Practice: Use mcg […]
^ Biology by Campbell & Reece, tenth edition. Ch. 6 "A Tour of the Cell". p. 98.
^ ^a ^b "On the extension of the range of SI prefixes". 2022-11-18. Retrieved 2023-02-05.
^ "Metric (SI) Prefixes". NIST.
^ Prefixes of the International System of Units, International Bureau of Weights and Measures (page visited on 9 May 2016).
^ (Unicode 1.0, 1991)
^ Unicode Technical Report #25
^ ISO 2955-1974: Information processing - Representations of SI and other units for use in systems with limited character sets (1st ed.). 1974.
^ "Table 2". ISO 2955-1983: lnformation processing - Representations of SI and other units for use in systems with limited character sets (PDF) (2nd ed.). 1983-05-15. Retrieved 2016-12-14. [1]
^ DIN 66030: Darstellungen von Einheitennamen in Systemen mit beschränktem Schriftzeichenvorrat (in German) (1st ed.). 1980.
^ "Neue Normen für die Informationsverarbeitung". Computerwoche (in German). 1981-01-09. Archived from the original on 2016-12-14. Retrieved 2016-12-14.
^ ^a ^b ^c Burtis, Carl A.; Ashwood, Edward R.; Bruns, David E. (2012), Tietz Textbook of Clinical Chemistry and Molecular Diagnostics (5th ed.), Elsevier Health Sciences, ISBN 978-1455759422.
^ "Commonly Used UCUM Codes for Healthcare Units". HL7 Deutschland e.V. 2015-11-21. Archived from the original on 2022-10-06. Retrieved 2022-12-24.

[4] Prefixes adopted before 1960 already existed before SI. The introduction of the CGS system was in 1873.

[Gold-1] International Bureau of Weights and Measures (2006), The International System of Units (SI) (PDF) (8th ed.), ISBN 92-822-2213-6, archived (PDF) from the original on 2021-06-04, retrieved 2021-12-16

[ISMP_2021-2] "ISMP List of Error-Prone Abbreviations, Symbols, and Dose Designations: Abbreviations for Doses/Measurement Units". Recommendations. Institute for Safe Medication Practices (ISMP). 2021-02-05. Archived from the original on 2022-12-24. Retrieved 2022-12-24. Error-Prone Abbreviations, Symbols, and Dose Designations: μg […] Intended Meaning: Microgram […] Misinterpretation: Mistaken as mg […] Best Practice: Use mcg […]

[3] Biology by Campbell & Reece, tenth edition. Ch. 6 "A Tour of the Cell". p. 98.

[newUnitAdoption-5] "On the extension of the range of SI prefixes". 2022-11-18. Retrieved 2023-02-05.

[6] "Metric (SI) Prefixes". NIST.

[7] Prefixes of the International System of Units, International Bureau of Weights and Measures (page visited on 9 May 2016).

[8] (Unicode 1.0, 1991)

[9] Unicode Technical Report #25

[ISO_2955-1974-10] ISO 2955-1974: Information processing - Representations of SI and other units for use in systems with limited character sets (1st ed.). 1974.

[ISO_2955-1983-11] "Table 2". ISO 2955-1983: lnformation processing - Representations of SI and other units for use in systems with limited character sets (PDF) (2nd ed.). 1983-05-15. Retrieved 2016-12-14. [1]

[DIN_66030_1980-12] DIN 66030: Darstellungen von Einheitennamen in Systemen mit beschränktem Schriftzeichenvorrat (in German) (1st ed.). 1980.

[Computerwoche_1981_DIN-13] "Neue Normen für die Informationsverarbeitung". Computerwoche (in German). 1981-01-09. Archived from the original on 2016-12-14. Retrieved 2016-12-14.

[Tietz_PT2241-14] Burtis, Carl A.; Ashwood, Edward R.; Bruns, David E. (2012), Tietz Textbook of Clinical Chemistry and Molecular Diagnostics (5th ed.), Elsevier Health Sciences, ISBN 978-1455759422.

[HL7_2015-15] "Commonly Used UCUM Codes for Healthcare Units". HL7 Deutschland e.V. 2015-11-21. Archived from the original on 2022-10-06. Retrieved 2022-12-24.

[1]

[2]

[3]

[nb 1]

[4]

[5]

[6]

[7]

[8]

[9]

[10]

[11]

[12]

[13]

[14]

@@ Line 1: / Line 1: @@
+{{Short description|Metric system unit prefix}}
 {{about|the SI prefix|other uses|Micro (disambiguation)}}
 {{Wiktionary|micro-}}
+{{use dmy dates|date=December 2022|cs1-dates=y}}
+'''''Micro''''' ([[Greek letter]] '''μ''', [[Mu (letter)|mu]], non-[[Italic type|italic]]) is a [[metric prefix|unit prefix]] in the [[metric system]] denoting a factor of 10<sup>−6</sup> (one [[millionth]]).<ref name="Gold">{{SIbrochure8th}}</ref> Confirmed in 1960, the prefix comes from the [[Ancient Greek|Greek]] {{lang|grc|[[wikt:μικρός|μικρός]]}} (''{{lang|grc-Latn|mikrós}}''), meaning "small".
+It is the only [[International System of Units|SI]] prefix which uses a character not from the [[Latin alphabet]]. In [[Unicode]], the symbol is represented by {{unichar|03BC}} or the legacy symbol {{unichar|00B5}}. The prefix "mc" is commonly used in healthcare or when the character "μ" is not available; for example, "mcg" commonly denotes a microgram.<ref name="ISMP_2021"/> The letter "u" is sometimes used instead of "μ" when non-[[Latin alphabet|Latin]] characters are not available.
-larger than [[https://en.wiktionary.org/wiki/pea-sized|pea-sized]]
+==Examples==
-'''Micro-''' (Greek letter '''μ''' or legacy micro symbol '''µ''') is a [[metric prefix|unit prefix]] in the [[metric system]] denoting a factor of 10<sup>−6</sup> (one [[millionth]]).<ref name="Gold">{{SIbrochure8th}}</ref> Confirmed in 1960, the prefix comes from the [[Ancient Greek|Greek]] {{lang|grc|[[wikt:μικρός|μικρός]]}} (''{{lang|grc-Latn|mikrós}}''), meaning "small".
+* Typical [[bacteria]] are 1 to 10 [[micrometre|micrometer]] (1–10 μm) in diameter.
+* [[Eukaryote|Eukaryotic cells]] are typically 10 to 100 micrometers in diameter.<ref>''Biology'' by Campbell & Reece, tenth edition. Ch. 6 "A Tour of the Cell". p. 98.</ref>
-The symbol for the prefix comes from the [[Greek letter]] μ ([[Mu (letter)|mu]]). It is the only [[International System of Units|SI]] prefix which uses a character not from the [[Latin alphabet]]. "mc" is commonly used as a prefix when the character "μ" is not available; for example, "mcg" commonly denotes a microgram (with some ambiguity, in that ''mcg'' could also be read as a ''micrigram'', i.e. 10<sup>−14</sup> g, albeit the "[[micri-]]" prefix is non-standard, not widely known, and now considered obsolete). Also the letter '''u''' instead of '''μ''' is allowed by one of the [[International Organization for Standardization|ISO]] documents.<ref>[http://isotc.iso.org/livelink/livelink/4289384/ISO_2955-1983E_repr_of_SI_units_with_limited_char_sets.pdf?func=doc.Fetch&nodeid=4289384 ISO 2955], table 2.</ref>
-Examples:
-* Typical [[bacteria]] are 1 to 10 [[micrometre]]s in diameter.
-* [[Eukaryote|Eukaryotic cells]] are typically 10 to 100 micrometres in diameter.<ref>''Biology'' by Campbell & Reece, tenth edition. Ch. 6 "A Tour of the Cell". p. 98.</ref>
 {{SI prefixes (infobox)}}
 ==Symbol encoding in character sets==
+The official symbol for the [[metric prefix|SI prefix]] ''micro'' is a [[mu (letter)|Greek lowercase mu]] (μ).<ref>[https://www.bipm.org/en/measurement-units/si-prefixes Prefixes of the International System of Units], [[International Bureau of Weights and Measures]] (page visited on 9 May 2016).</ref> For reasons stemming from its design, [[Unicode]] has two different character codes for the letter, with slightly different appearance in some fonts, although most fonts use the same [[glyph#Typography|glyph]]. {{unichar|00B5|MICRO SIGN}} ({{keypress|Alt|0181}}) is in the "Latin-1 Supplement" range identical to [[ISO/IEC 8859-1]] (since 1987),<ref>(Unicode 1.0, 1991)</ref> residing at this code point also in [[DEC MCS]] (since 1983) and [[ECMA-94]] (since 1985). {{unichar|03BC|GREEK SMALL LETTER MU}} ({{keypress|Alt|956}}) is in the Greek range. According to [[The Unicode Consortium]], the Greek letter character is preferred,<ref>[https://www.unicode.org/reports/tr25 Unicode Technical Report #25]</ref> but implementations must recognize the micro sign as well, for [[Unicode compatibility characters|compatibility with legacy character sets]]. This distinction also occurs in some legacy code pages, notably [[Windows-1253]].
+In circumstances in which only the [[Latin alphabet]] is available, [[International Standards Organization|ISO]] 2955 (since 1974,<ref name="ISO_2955-1974">{{cite book |title=ISO 2955-1974: Information processing - Representations of SI and other units for use in systems with limited character sets |edition=1st |date=1974}}</ref> withdrawn 2001<ref name="ISO_2955-1983">{{cite book |url=http://isotc.iso.org/livelink/livelink/4289384/ISO_2955-1983E_repr_of_SI_units_with_limited_char_sets.pdf?func=doc.Fetch&nodeid=4289384 |title=ISO 2955-1983: lnformation processing - Representations of SI and other units for use in systems with limited character sets |date=1983-05-15 |edition=2nd |chapter=Table 2 |access-date=2016-12-14}} [http://www.bgu.ac.il/~averbukh/ISO_2955-1983E.pdf]</ref>), [[Deutsches Institut für Normung|DIN]] 66030 (since 1980<ref name="DIN_66030_1980">{{cite book |title=DIN 66030: Darstellungen von Einheitennamen in Systemen mit beschränktem Schriftzeichenvorrat |language=de |edition=1st |date=1980}}</ref><ref name="Computerwoche_1981_DIN">{{cite journal |title=Neue Normen für die Informationsverarbeitung |language=de |journal=[[Computerwoche]] |date=1981-01-09 |url=http://www.computerwoche.de/a/neue-normen-fuer-die-informationsverarbeitung,1184901 |access-date=2016-12-14 |url-status=live |archive-url=https://web.archive.org/web/20161214025700/http://www.computerwoche.de/a/neue-normen-fuer-die-informationsverarbeitung%2C1184901 |archive-date=2016-12-14}}</ref>) and [[British Standards Institution|BS]] 6430 (since 1983) allow the prefix <code>μ</code> to be substituted by the letter <code>[[u]]</code> (or even <code>[[U]]</code>, if lowercase letters are not available), as, for example, in <code>um</code> for <code>μm</code>, or <code>uF</code> for <code>μF</code>, or in the common abbreviation <code>UC</code> for [[microcontroller]] (μC).
-The official symbol for the [[metric prefix|SI prefix]] ''micro-'' is a [[mu (letter)|Greek lowercase mu]] (μ).<ref>[http://www.bipm.org/en/measurement-units/prefixes.html Prefixes of the International System of Units], [[International Bureau of Weights and Measures]] (page visited on 9 May 2016).</ref> For reasons stemming from its design, there are two different characters in [[Unicode]], which appear slightly different in some fonts, although most fonts use the same [[glyph#Typography|glyph]]. The micro sign (µ) is encoded in the "Latin-1 Supplement" range identical to [[ISO/IEC 8859-1]] (since 1987), at <code>U+00B5</code> ({{keypress|Alt|0181}}),<ref>(Unicode 1.0, 1991)</ref> residing at this code point also in [[DEC MCS]] (since 1983) and [[ECMA-94]] (since 1985). The Greek letter (μ) is encoded in the Greek range at <code>U+03BC</code> ({{keypress|Alt|956}}). According to [[The Unicode Consortium]], the Greek letter character is preferred,<ref>[https://www.unicode.org/reports/tr25 Unicode Technical Report #25]</ref> but implementations must recognize the micro sign as well. This distinction also occurs in some legacy code pages, notably [[Windows-1253]].
+Similarly, capacitor values according to the [[RKM code]] defined in [[International Electrotechnical Commission|IEC]] 60062 (since 1952) can be written as <code>4u7</code> (or <code>4U7</code>) instead of <code>4μ7</code> if the Greek letter <code>μ</code> is not available.
+The [[CJK Compatibility]] block contains square forms of some Japanese [[katakana]] measure and currency units.
-In circumstances in which only the [[Latin alphabet]] is available, [[ISO 2955]] (1974,<ref name="ISO_2955-1974">{{cite book |title=ISO 2955-1974: lnformation processing - Representations of SI and other units for use in systems with limited character sets |edition=1st |date=1974}}</ref> 1983<ref name="ISO_2955-1983">{{cite book |title=ISO 2955-1983: lnformation processing - Representations of SI and other units for use in systems with limited character sets |chapter=Table 2 |date=1983-05-15 |edition=2nd |url=http://isotc.iso.org/livelink/livelink/4289384/ISO_2955-1983E_repr_of_SI_units_with_limited_char_sets.pdf?func=doc.Fetch&nodeid=4289384 |access-date=2016-12-14}} [http://www.bgu.ac.il/~averbukh/ISO_2955-1983E.pdf<!-- https://web.archive.org/web/20161214025341/http://www.bgu.ac.il/~averbukh/ISO_2955-1983E.pdf -->]</ref>), [[DIN 66030]] (Vornorm 1973;<ref name="Vornorm_DIN_66030_1973">{{cite book |title=Vornorm DIN 66030 |language=de |trans-title=Preliminary standard DIN 66030 |date=January 1973}}</ref> 1980,<ref name="DIN_66030_1980">{{cite book |title=DIN 66030: Darstellungen von Einheitennamen in Systemen mit beschränktem Schriftzeichenvorrat |language=de |edition=1st |date=1980}}</ref><ref name="Computerwoche_1981_DIN">{{cite journal |title=Neue Normen für die Informationsverarbeitung |language=de |journal=[[Computerwoche]] |date=1981-01-09 |url=http://www.computerwoche.de/a/neue-normen-fuer-die-informationsverarbeitung,1184901 |access-date=2016-12-14 |url-status=live |archive-url=https://web.archive.org/web/20161214025700/http://www.computerwoche.de/a/neue-normen-fuer-die-informationsverarbeitung%2C1184901 |archive-date=2016-12-14}}</ref> 2002<ref name="DIN_66030:2002-05">{{cite book |title=DIN 66030:2002-05 - Informationstechnik - Darstellung von Einheitennamen in Systemen mit beschränktem Schriftzeichenvorrat |language=de |trans-title=Information technology - Representation of SI and other units in systems with limited character sets |date=May 2002 |publisher={{ill|Beuth Verlag|de}} |url=https://www.beuth.de/de/norm/din-66030/50570368 |access-date=2016-12-14}}</ref>) and [[BS 6430]] (1983) allow the prefix <code>μ</code> to be substituted by the letter <code>[[u]]</code> (or even <code>[[U]]</code>, if lowercase letters are not available), as, for example, in <code>um</code> for <code>μm</code>, or <code>uF</code> for <code>μF</code>.
+{{Unichar|3343}} corresponds to {{lang|ja|マイクロ}} {{transl|ja|maikuro}}.
-Similar, capacitor values according to the [[RKM code]] defined in [[IEC 60062]] (IEC 62) (since 1952), [[EN 60062]], [[DIN 40825]] (1973), [[BS 1852]] (1974), [[IS 8186]] (1976) etc. can be written as <code>4u7</code> (or <code>4U7</code>) instead of <code>4μ7</code> if the Greek letter <code>μ</code> is not available.
 ==Other abbreviating conventions==
-In some [[health care]] institutions, house rules deprecate the standard symbol for [[microgram]], "μg", in prescribing or chart recording, because of the risk of giving an incorrect dose because of the misreading of poor handwriting.<ref name="Tietz_PT2241">{{Citation |last1=Burtis |first1=Carl A. |last2=Ashwood |first2=Edward R. |last3=Bruns |first3=David E. |year=2012 |title=Tietz Textbook of Clinical Chemistry and Molecular Diagnostics |isbn=978-1455759422 |edition=5th |url=https://books.google.com/books?id=BBLRUI4aHhkC&pg=PT2241 |postscript=.}}</ref> The two alternatives are to abbreviate as "mcg"<ref name="Tietz_PT2241"/> or to write out "microgram" in full (see also [[List of abbreviations used in medical prescriptions]]). But this deprecation, focused on avoiding incorrect dosing in contexts where handwriting is often present, does not extend to all health-care contexts and institutions (for example, some clinical laboratories' reports adhere to it, whereas others do not<ref name="Tietz_PT2241"/>), and in physical sciences academia, "μg" remains the sole official abbreviation.
+In some [[health care]] institutions, house rules deprecate the standard symbol for [[microgram]], "μg", in prescribing or chart recording, because of the risk of giving an incorrect dose because of the misreading of poor handwriting.<ref name="Tietz_PT2241">{{Citation |last1=Burtis |first1=Carl A. |last2=Ashwood |first2=Edward R. |last3=Bruns |first3=David E. |year=2012 |title=Tietz Textbook of Clinical Chemistry and Molecular Diagnostics |publisher=Elsevier Health Sciences |isbn=978-1455759422 |edition=5th |url=https://books.google.com/books?id=BBLRUI4aHhkC&pg=PT2241 |postscript=.}}</ref> The two alternatives are to abbreviate as "mcg"<ref name="Tietz_PT2241"/><ref name="ISMP_2021"/> or to write out "microgram" in full (see also [[List of abbreviations used in medical prescriptions]]). The alternative abbreviation may be ambiguous in rare circumstances in that ''mcg'' could also be read as a ''micrigram'', i.e. 10<sup>−14</sup> g; however the prefix ''[[micri-|micri]]'' is not standard, nor widely known, and is considered obsolete. This deprecation, focused on avoiding incorrect dosing in contexts where handwriting is often present, does not extend to all health-care contexts and institutions (for example, some clinical laboratories' reports adhere to it, whereas others do not<ref name="Tietz_PT2241"/>), and in [[physical sciences]] research, "μg" remains the sole official abbreviation.
-In medical data exchange according to the [[Health Level 7]] (HL7) standard, the μ can be replaced by u as well.<ref name="HL7">{{cite web |url=http://download.hl7.de/documents/ucum/ucumdata.html |title=Commonly Used UCUM Codes for Healthcare Units |access-date=2015-11-21 |publisher=HL7 Deutschland e.V.}}</ref>
+In medical data exchange according to the [[Health Level 7]] (HL7) standard, the μ can be replaced by u as well.<ref name="HL7_2015"/>
 ==See also==
@@ Line 34: / Line 36: @@
 ==References==
-{{reflist}}
+{{reflist|refs=
+<ref name="HL7_2015">{{cite web |title=Commonly Used UCUM Codes for Healthcare Units |date=2015-11-21 |publisher=HL7 Deutschland e.V. |url=https://download.hl7.de/documents/ucum/ucumdata.html |access-date=2022-12-24 |url-status=live |archive-url=https://web.archive.org/web/20221006180404/https://download.hl7.de/documents/ucum/ucumdata.html |archive-date=2022-10-06}}</ref>
+<!-- <ref name="HL7_2022">{{cite web |title=Commonly Used UCUM Codes for Healthcare Units |date=2015-11-21 |publisher=HL7 Deutschland e.V. |url=https://howtotypesymbols.com/how-to-type-mu-micro-symbol-in-word-and-mac/ |access-date=2023-01-14 |url-status=live |archive-url=https://web.archive.org/web/20221006180404/https://download.hl7.de/documents/ucum/ucumdata.html |archive-date=2022-10-06}}</ref> -->
+<ref name="ISMP_2021">{{cite web |title=ISMP List of Error-Prone Abbreviations, Symbols, and Dose Designations: Abbreviations for Doses/Measurement Units |date=2021-02-05 |work=Recommendations |publisher=[[Institute for Safe Medication Practices]] (ISMP) |url=https://www.ismp.org/recommendations/error-prone-abbreviations-list |access-date=2022-12-24 |url-status=live |archive-url=https://web.archive.org/web/20221224213621/https://www.ismp.org/recommendations/error-prone-abbreviations-list |archive-date=2022-12-24 |quote=Error-Prone Abbreviations, Symbols, and Dose Designations: μg […] Intended Meaning: Microgram […] Misinterpretation: Mistaken as mg […] Best Practice: Use mcg […]}}</ref>
+}}
 {{Portal bar|Physics}}
 [[Category:SI prefixes]]
-[[he:תחיליות במערכת היחידות הבינלאומית#מיקרו]]
-[[nl:Micro]]
-[[simple:Micro-]]