XML Help for PubMed Data Providers

Data Provider Quick Start

How do I interpret the PubMed Loader Report?

Below is an example of a typical Loader Report. Contact us at publisher@ncbi.nlm.nih.gov if you have not received the Loader Report within one business day of submitting your file.

Journal|Year|Volume|Issue|First Page|First Author|Article ID|PubMed ID

File GSEv40i3.xml(6 articles)

Genet Sel Evol|2008|40|3|241|Doeschl-Wilson AB|g07060|18400148

Genet Sel Evol|2008|40|3|265|Lee SH|g07054|18400149

Genet Sel Evol|2008|40|3|279|Ibanez-Escriche N|g07028|18400150

Genet Sel Evol|2008|40|3|295|Tarres J|g07027|18400151

Genet Sel Evol|2008|40|3|309|Pritchard T|g07035|18400152

Genet Sel Evol|2008|40|3|321|Cinkulov M|g07062|18400153

Total processed: 6 article(s), 6 were created.

Total processed: # article(s), # were created, # were replaced, # were rejected.

The report contains the filename (XGEv133i2.xml), followed by the number of articles in the file. This is followed by a listing of articles created with each article containing the following fields: MEDLINE Title Abbreviation, Year, Volume, Issue, First Page, First Listed Author, Article ID (if present in the file), and PubMed Identifier (PMID). Following the batch of articles is a "Total processed" message indicating the number of articles processed from the uploaded file and the number created, replaced, and/or rejected.

Rejected articles in a Loader Report will often be annotated with error messages. Here is a list of possible error messages:

Cannot replace Article: Article does not have " [PubMed – as supplied by publisher] " status. The <Replaces> tag can only be used if the citation is currently in the " [PubMed – as supplied by publisher] " status. Please see our Correcting Errors in PubMed documentation for more information.

Cannot find article by ID. The doi or pii listed in the <Replaces> tag IdType attribute does not exist in a PubMed citation. Please verify that the doi or pii is accurate. If necessary remove the <Replaces> tag and reload the file to create the article rather than ‘replace’ a non-existent PubMed citation.

Article matches PMID = , which is not in " [PubMed – as supplied by publisher] " status. This message means the data is already in PubMed and it cannot be modified by a Replacement file.

ISSN not found in NCBI database: ISSN= Title= . There are two actions you can take in response to this: 1) Verify the ISSN is correct. 2) Confirm that you have notified the Data Provider Support Team of any recent title changes.

Not a current MEDLINE journal: ISSN= Title= . There are two actions you can take in response to this: 1) Verify the ISSN is correct. 2) Confirm that you have notified the Data Provider Support Team of any recent title changes.

Article matches PMID= To update use Replaces tag. Please refer to the Instructions for Replacement Files documentation for more information.

Cannot replace Article: PMID does not exist. NLM has deleted the PMID or you have provided an invalid PMID number. Please refer to the "How do I determine if a PMID has been deleted?" question.

Wrong provider. Verify that you have received Approval from the Data Provider Support Team.

Partial match. Submitted citation matched an existing PubMed citation. Volume, issue, page and Article Id matched but there are differences in the author, title, or publication date tags.

Invalid Year / Invalid Month / Invalid Day. The message will specify whether the invalid date appeared in the PubDate tag within <Journal> or the PubDate tag within <History>. <Year> can only contain 4-digit ranging between 1966 and 2010. <Month> can only contain the numbers 1-12, the month (in English) or the first three letters of the English months. NOTE: The only PubStatus attribute that allows for a dual month in <Month> is ppublish. <Day> can only contain the numbers 1-31.

Month tag is missing or empty; Day tag is present.

ISSN tag is missing or empty.

Both Volume and Issue tags are missing or empty. A valid file must contain a value in the Volume tag or the Issue tag, or both.

Replaces tag has invalid symbols or is empty. <Replaces> tag cannot be empty. Please refer to the Instructions for Replacement Files documentation for more information.

FirstPage tag is missing or empty. In a <PubDate PubStatus ="ppublish" article the <FirstPage> tag cannot be empty.

FirstPage tag is missing or empty; LastPage is present. If an article is only one page in length the value should appear in the <FirstPage> tag not the <LastPage> tag.

FirstPage / LastPage tag has invalid symbols. Invalid symbols are anything other than letters or numbers.

Abstract is too short. The text within the <Abstract> tags must be more than 50 characters in length. If the Article does not have an abstract then the <Abstract> tag should be left empty. The phrase "No Abstract Available" is not necessary in XML files.

The following is a subset of the ISO 639 standard (more...)

The following is a subset of the ISO 639 standard for language codes.

CODE	LANGUAGE
EN	English
AF	Afrikaans
SQ	Albanian
AM	Amharic
AR	Arabic
AZ	Azerbaijani
HY	Armenian
BN	Bengali
BS	Bosnian
BG	Bulgarian
CA	Catalan
ZH	Chinese
HR	Croatian
CS	Czech
DA	Danish
NL	Dutch
EO	Esperanto
ET	Estonian
FI	Finnish
FR	French
GD	Scottish Gaelic
KA	Georgian
DE	German
EL	Greek, Modern
HE	Hebrew
HU	Hungarian
HI	Hindi
IS	Icelandic
ID	Indonesian
IT	Italian
JA	Japanese
RW	Kinyarwanda
KO	Korean
LA	Latin
LV	Latvian
LT	Lithuanian
MK	Macedonian
ML	Malayalam
MI	Maori
MS	Malay
MU	Multilingual
NO	Norwegian
FA	Persian
PL	Polish
PT	Portuguese
PS	Pushto
RO	Romanian
RU	Russian
SA	Sanskrit
SR	Serbo-Croatian, Cyrillic
SR	Serbo-Croatian, Roman
SK	Slovak
SL	Slovene
ES	Spanish
SV	Swedish
TH	Thai
TR	Turkish
UK	Ukrainian
UR	Urdu
VI	Vietnamese
CY	Welsh

Unknown Language. See our list of accepted language codes.

FirstName / LastName / CollectiveName tag is missing or empty. Message will specify which Author tag the error occurred in. (Author 1, Author 2, etc.) If either the FirstName or LastName tag is present and contains text both must be present and contain text. If neither the FirstName nor LastName tag is present then the CollectiveName tag must be present and contain text.

FirstName / LastName contains invalid characters. Message will specify which Author tag the error occurred in. (Author 1, Author 2, etc.). The following are invalid characters:

! " # $ % & @ ( ) * + / ; : ` < = > ? ^ { | } [ \ ]

Ahead-of-print Article must have "pii" or "doi". See our page "All About Ahead of Print" for more details

Invalid Ahead of Print date. Ahead of Print files can not have an electronic publication date greater than eighteen (18) months prior to the date of uploading to PubMed.

Cannot replace Article: Replacement file must use the original ArticleIds

Cannot replace Article: ArticleIds do not match. Contact to change ArticleIds.LinkOut

Bibliographic data does not match.

A rejected article or file will not necessarily produce an error message in the loader report. Some common errors that do not produce them are:

The presence of an incomplete entity. All entities must begin with an ampersand (&) and end with a semi-colon (;).

The presence of a stand-alone ampersand (&). When an ampersand is not part of an entity it must be represented by this entity &amp;

The presence of a stand-alone less than (<) or greater than (>) symbol. When less than or greater than symbols are not part of XML tags they must be represented by the entities &lt; and &gt; respectively.

The presence of extraneous spaces and/or line breaks within XML tags.

The file or an article within the file was not formatted in accordance with PubMed specifications. Additional information on the required XML format is available in the PubMed DTD.

PubMed XML Tagged Format

The XML tags are listed below followed by descriptions. Additional information on XML tagged format is available at the following Web sites: W3Schools, XML.com, and OASIS.

This format is required for submission of citation and abstract data to PubMed. Other formats are not accepted. Only journals that are already approved for inclusion in PubMed/MEDLINE should be submitted. See the Data Provider Quick Start for more information about journals indexed for MEDLINE.

If you wish to have non-ASCII characters in your citations you must use standard SGML entity names. It is not possible to keep a separate translation table for each publisher, given the number of possible non-ASCII characters.

Links to the journal Web site, if available, may be submitted using LinkOut.

Section Contents

• XML Tag Descriptions

• SGML Data Entities for PubMed Submissions

• XML File Examples

• Subset of ISO 639 Language Codes

• PubMed DTD

XML Tag Descriptions

The following is a glossary of the tags defined in the PubMed DTD. Click on each of the tag names below for more information. You can also view an Example of a Standard XML File.

Data Tags (R = Required, O = Optional O/R = Optional or Required). Tag names are case sensitive. Required tags must be included; optional tags must be included only if the data requested appears in the print or electronic article. Optional or Required tags are dependent on the use of other tags.

Example of a Standard XML file

Follow the links for more information about each tag.

Example of a Non-English XML file

Example of an Ahead of Print XML file

Example of a Replaces XML file

SGML Data Entities for PubMed Submissions

Here is a list of commonly used SGML entities that can be used in XML files uploaded to PubMed. For each entity listed we have provided the hexadecimal UNICODE value, the translation as it will appear in PubMed, and the meaning. Though they are not listed, we also accept the decimal UNICODE values for the entities listed here. This is not a comprehensive list of accepted characters.

When creating your XML file, please keep in mind the following:

• If it is possible to use an ASCII character to represent an entity, please use the ASCII character. For example, general punctuation such as quotation marks, colons, and number signs may be created with keyboard characters. Note that there are three exceptions to this rule: We require you to use an SGML entity instead of ASCII when creating an ampersand (&) [use &amp;], a less than symbol (<) [use &lt;], and a greater than symbol (>) [use &gt;] Where these three occur in tag names or entities, simply use the ASCII characters. For example:

Entities:
&uuml; NOT &amp;uuml;
&apos; NOT &amp;apos;

Tag Names:
<Month> NOT &lt;Month&gt;

Text:
[P &lt; 0.01] NOT [P < 0.01]

• We prefer that you use SGML entities (first column), but can accept both decimal and hexadecimal UNICODE character references.

• If you wish to use a UNICODE value to represent your character, you must place it in the following format: ampersand (&) followed by a pound sign (#) followed by the UNICODE value followed by a semicolon (;). For example, use &#x00B0; (hexadecimal value) or &#176; (decimal value) to represent a degree symbol.

• Use  to indicate superscript, and <inf> </inf> to represent inferior or subscript characters in the <ArticleTitle> and <Abstract> tags.

• Diacritics must be represented with SGML entities for the characters to appear correctly in PubMed. This is required for two reasons: first, a user can view diacritics in the XML display of a PubMed citation if their browser is set to translate the UNICODE/UTF-8 character set and second, many licensees of the MEDLINE database world-wide have the ability to display diacritics and therefore value this coding.

• You can test your entities with our PubMed Citation XML File Validator. In addition to testing the structure of your XML files, it can determine whether the entities you are using are accepted by our parser.

• 

  ISO Latin-1

  ISO Latin-1

  Entity	Unicode	PubMed Displays as	Meaning
  á	á	á	small a, acute accent
  Á	Á	Á	capital A, acute accent
  â	â	â	small a, circumflex accent
  Â	Â	Â	capital A, circumflex accent
  à	à	à	small a, grave accent
  À	À	À	capital A, grave accent
  å	å	å	small a, ring
  Å	Å	Å	capital A, ring
  ã	ã	ã	small a, tilde
  Ã	Ã	Ã	capital A, tilde
  ä	ä	ä	small a, dieresis or umlaut mark
  Ä	Ä	Ä	capital A, dieresis or umlaut mark
  æ	æ	æ	small ae diphthong (ligature)
  Æ	Æ	Æ	capital AE diphthong (ligature)
  ç	ç	ç	small c, cedilla
  Ç	Ç	Ç	capital C, cedilla
  ð	ð	ð	small eth, Icelandic
  Ð	Ð	Ð	capital Eth, Icelandic
  é	é	é	small e, acute accent
  É	É	É	capital E, acute accent
  ê	ê	ê	small e, circumflex accent
  Ê	Ê	Ê	capital E, circumflex accent
  è	è	è	small e, grave accent
  È	È	È	capital E, grave accent
  ë	ë	ë	esmall e, dieresis or umlaut mark
  Ë	Ë	Ë	capital E, dieresis or umlaut mark
  í	í	í	small i, acute accent
  Í	Í	Í	capital I, acute accent
  î	î	î	small i, circumflex accent
  Î	Î	Î	capital I, circumflex accent
  ì	ì	ì	ismall i, grave accent
  Ì	Ì	Ì	capital I, grave accent
  ï	ï	ï	small i, dieresis or umlaut mark
  Ï	Ï	Ï	capital I, dieresis or umlaut mark
  ñ	ñ	ñ	small n, tilde
  Ñ	Ñ	Ñ	capital N, tilde
  ó	ó	ó	small o, acute accent
  Ó	Ó	Ó	capital O, acute accent
  ô	ô	ô	small o, circumflex accent
  Ô	Ô	Ô	capital O, circumflex accent
  ò	ò	ò	small o, grave accent
  Ò	Ò	Ò	capital O, grave accent
  ø	ø	ø	small o, slash
  Ø	Ø	Ø	capital O, slash
  õ	õ	õ	small o, tilde
  Õ	Õ	Õ	capital O, tilde
  ö	ö	ö	small o, dieresis or umlaut mark
  Ö	Ö	Ö	capital O, dieresis or umlaut mark
  ß	ß	ß	small sharp s, German (sz ligature)
  þ	þ	þ	small thorn, Icelandic
  Þ	Þ	Þ	capital THORN, Icelandic
  ú	ú	ú	small u, acute accent
  Ú	Ú	Ú	capital U, acute accent
  û	û	û	small u, circumflex accent
  Û	Û	Û	capital U, circumflex accent
  ù	ù	ù	small u, grave accent
  Ù	Ù	Ù	capital U, grave accent
  ü	ü	ü	small u, dieresis or umlaut mark
  Ü	Ü	Ü	capital U, dieresis or umlaut mark
  ý	ý	ý	small y, acute accent
  Ý	Ý	Ý	capital Y, acute accent
  ÿ	ÿ	ÿ	small y, dieresis or umlaut mark

  ISO Latin-1

• 

  ISO Latin-2

  ISO Latin-2

  Entity	Unicode	PubMed Displays as	Meaning
  ă	ă	ă	small a, breve
  Ă	Ă	Ă	capital A, breve
  ā	ā	ā	small a, macron
  Ā	Ā	Ā	capital A, macron
  ą	ą	ą	small a, ogonek
  Ą	Ą	Ą	capital A, ogonek
  ć	ć	ć	small c, acute accent
  Ć	Ć	Ć	capital C, acute accent
  č	č	č	small c, caron
  Č	Č	Č	capital C, caron
  ĉ	ĉ	ĉ	small c, circumflex accent
  Ĉ	Ĉ	Ĉ	capital C, circumflex accent
  ċ	ċ	ċ	small c, dot above
  Ċ	Ċ	Ċ	capital C, dot above
  ď	ď	ď	small d, caron
  Ď	Ď	Ď	capital D, caron
  đ	đ	đ	small d, stroke
  Đ	Đ	Đ	capital D, stroke
  ě	ě	ě	small e, caron
  Ě	Ě	Ě	capital E, caron
  ė	ė	ė	small e, dot above
  Ė	Ė	Ė	capital E, dot above
  ē	ē	ē	small e, macron
  Ē	Ē	Ē	capital E, macron
  ę	ę	ę	small e, ogonek
  Ę	Ę	Ę	capital E, ogonek
  ǵ	ǵ		small g, acute accent
  ğ	ğ	ğ	small g, breve
  Ğ	Ğ	Ğ	capital G, breve
  Ģ	Ģ	Ģ	capital G, cedilla
  ĝ	ĝ	ĝ	small g, circumflex accent
  Ĝ	Ĝ	Ĝ	capital G, circumflex accent
  ġ	ġ	ġ	small g, dot above
  Ġ	Ġ	Ġ	capital G, dot above
  ĥ	ĥ	ĥ	small h, circumflex accent
  Ĥ	Ĥ	Ĥ	capital H, circumflex accent
  ħ	ħ	ħ	small h, stroke
  Ħ	Ħ	Ħ	capital H, stroke
  İ	İ	İ	capital I, dot above
  Ī	Ī	Ī	capital I, macron
  ī	ī	ī	small i, macron
  ij	ij	ij	small ij ligature
  IJ	IJ	IJ	capital IJ ligature
  ı	ı	ı	small i, no dot
  į	į	į	small i, ogonek
  Į	Į	Į	capital I, ogonek
  ĩ	ĩ	ĩ	small i, tilde
  Ĩ	Ĩ	Ĩ	capital I, tilde
  ĵ	ĵ	ĵ	small j, circumflex accent
  Ĵ	Ĵ	Ĵ	capital J, circumflex accent
  ķ	ķ	ķ	small k, cedilla
  Ķ	Ķ	Ķ	capital K, cedilla
  ĸ	ĸ	ĸ	small k, Greenlandic
  ĺ	ĺ	ĺ	small l, acute accent
  Ĺ	Ĺ	Ĺ	capital L, acute accent
  ľ	ľ	ľ	small l, caron
  Ľ	Ľ	Ľ	capital L, caron
  ļ	ļ	ļ	small l, cedilla
  Ļ	Ļ	Ļ	capital L, cedilla
  ŀ	ŀ	ŀ	small l, middle dot
  Ŀ	Ŀ	Ŀ	capital L, middle dot
  ł	ł	ł	small l, stroke
  Ł	Ł	Ł	capital L, stroke
  ń	ń	ń	small n, acute accent
  Ń	Ń	Ń	capital N, acute accent
  ŋ	ŋ	ŋ	small eng, Lapp
  Ŋ	Ŋ	Ŋ	capital ENG, Lapp
  ʼn	ʼn	ʼn	small n, apostrophe
  ň	ň	ň	small n, caron
  Ň	Ň	Ň	capital N, caron
  ņ	ņ	ņ	small n, cedilla
  Ņ	Ņ	Ņ	capital N, cedilla
  ő	ő	ő	small o, double acute accent
  Ő	Ő	Ő	capital O, double acute accent
  Ō	Ō	Ō	capital O, macron
  ō	ō	ō	small o, macron
  œ	œ	œ	small oe ligature
  Œ	Œ	Œ	capital OE ligature
  ŕ	ŕ	ŕ	small r, acute accent
  Ŕ	Ŕ	Ŕ	capital R, acute accent
  ř	ř	ř	small r, caron
  Ř	Ř	Ř	capital R, caron
  ŗ	ŗ	ŗ	small r, cedilla
  Ŗ	Ŗ	Ŗ	capital R, cedilla
  ś	ś	ś	small s, acute accent
  Ś	Ś	Ś	capital S, acute accent
  š	š	š	small s, caron
  Š	Š	Š	capital S, caron
  ş	ş	ş	small s, cedilla
  Ş	Ş	Ş	capital S, cedilla
  ŝ	ŝ	ŝ	small s, circumflex accent
  Ŝ	Ŝ	Ŝ	capital S, circumflex accent
  ť	ť	ť	small t, caron
  Ť	Ť	Ť	capital T, caron
  ţ	ţ	ţ	small t, cedilla
  Ţ	Ţ	Ţ	capital T, cedilla
  ŧ	ŧ	ŧ	small t, stroke
  Ŧ	Ŧ	Ŧ	capital T, stroke
  ŭ	ŭ	ŭ	small u, breve
  Ŭ	Ŭ	Ŭ	capital U, breve
  ű	ű	ű	small u, double acute accent
  Ű	Ű	Ű	capital U, double acute accent
  ū	ū	ū	small u, macron
  Ū	Ū	Ū	capital U, macron
  ų	ų	ų	small u, ogonek
  Ų	Ų	Ų	capital U, ogonek
  ů	ů	ů	small u, ring
  Ů	Ů	Ů	capital U, ring
  ũ	ũ	ũ	small u, tilde
  Ũ	Ũ	Ũ	capital U, tilde
  ŵ	ŵ	ŵ	small w, circumflex accent
  Ŵ	Ŵ	Ŵ	capital W, circumflex accent
  ŷ	ŷ	ŷ	small y, circumflex accent
  Ŷ	Ŷ	Ŷ	capital Y, circumflex accent
  Ÿ	Ÿ	Ÿ	capital Y, dieresis or umlaut mark
  ź	ź	ź	small z, acute accent
  Ź	Ź	Ź	capital Z, acute accent
  ž	ž	ž	small z, caron
  Ž	Ž	Ž	capital Z, caron
  ż	ż	ż	small z, dot above
  Ż	Ż	Ż	capital Z, dot above

  ISO Latin-2

• 

  Publishing

  Publishing

  Entity	Unicode	PubMed Displays as	Meaning
   	 		em space
   	 		en space (1/2-em)
   	 		1/3-em space
   	 		1/4-em space
   	 		digit space (width of a number)
   	 		punctuation space (width of comma)
   	 		thin space (1/6-em)
   	 		hair space
  —	—	-	em dash
  –	–	-	en dash
  ‐	‐	-	hyphen (true graphic)
  ␣	␣		significant blank symbol
  …	…	em leader	ellipsis (horizontal)
  ‥	‥	..	double baseline dot (en leader)
  ⅓	⅓	(1/3)	fraction one-third
  ⅔	⅔	(2/3)	fraction two-thirds
  ⅕	⅕	(1/5)	fraction one-fifth
  ⅖	⅖	(2/5)	fraction two-fifths
  ⅗	⅗	(3/5)	fraction three-fifths
  ⅘	⅘	(4/5)	fraction four-fifths
  ⅙	⅙	(1/6)	fraction one-sixth
  ⅚	⅚	(5/6)	fraction five-sixths
  ℅	℅	in-care-of	in-care-of symbol
  █	█	full block	full block
  ▀	▀	upper half block	upper half block
  ▄	▄	lower half block	lower half block
  ░	░	25% shaded block	25% shaded block
  ▒	▒	50% shaded block	50% shaded block
  ▓	▓	75% shaded block	75% shaded block
  ▮	▮	histogram marker	histogram marker
  ○	○	o	circle, open
  □	□	square	square, open
  ▭	▭	rectangle	rectangle, open
  ▵	▵	triangle up	up triangle, open
  ▿	▿	triangle down	down triangle, open
  ☆	⋆	small star, filled	star, open
  •	•	*	round bullet, filled
  ▪	▪	blacksquare, square, filled	sq bullet, filled
  ▴	▴	black triangle	up triangle , filled
  ▾	▾	black triangle down	down triangle , filled
  ◂	◂	black triangle left	left triangle , filled
  ▸	▸	black triangle right	right triangle , filled
  ♣	♣	club suit symbol	club suit symbol
  ♦	♦	diamond	diamond suit symbol
  ♥	♡	heart	heart suit symbol
  ♠	♠	spades	spades suit symbol
  ✠	✠	maltese cross	maltese cross
  †	†	dagger	dagger
  ‡	‡	double dagger	double dagger
  ✓	✓	check mark	tick, check mark
  ✗	✗	ballot cross	ballot cross
  ♯	♯	musical sharp	musical sharp
  ♭	♭	musical flat	musical flat
  ♂	♂	male symbol	male symbol
  ♀	♀	female symbol	female symbol
  ☎	☎	telephone symbol	telephone symbol
  ⌕	⌕	telephone recorder symbol	telephone recorder symbol
  ℗	℗	sound recording copyright sign	sound recording copyright sign
  ⁁	⁁	insertion mark	caret (insertion mark)
  ‚	‚	'	rising single quote, left (low)
  „	„	"	rising double quote, left (low)
  …	…	em leader	em leader
  ”	”	"	double quote, right (high)
  ’	’	'	single quote, right (high)
  ⋮	⋮	vertical ellipsis	vellipvertical ellipsis
  ⁃	⁃	rectangle	filled hyphen bullet rectangle
  ◊	◊	lozenge	lozenge or total mark
  ◃	◃	triangle left	left triangle, open
  ▹	▹	triangle right	right triangle, open
  ★	★	bigstar	star, filled
  ♮	♮	music natural	music natural
  ℞	℞	Rx	pharmaceutical prescription (Rx)
  ✶	✶	sextile	sextile (6-pointed star)
  ⌖	⌖	register mark or target	mark or target
  ⌍	⌍	downward left crop mark	left crop mark
  ⌌	⌌	downward right crop mark	right crop mark
  ⌏	⌏	upward left crop mark	left crop mark
  ⌎	⌎	upward right crop mark	right crop mark

  Publishing

• 

  General Technical

  General Technical

  Entity	Unicode	PubMed Displays as	Meaning
  ℵ	ℵ	aleph	aleph, Hebrew
  ∧	∧	wedge	logical and
  &ang90;	∟	90 degree angle	right (90 degree) angle
  ∢	∢	angle-spherical	angle-spherical
  ≈	≈	approximately	approximate
  ∵	∵	because	because
  ⊥	⊥	perpendicular	perpendicular
  ∩	∩	intersection	intersection
  ≅	≅	congruent with	congruent with
  ∮	∮	contour integral operator	contour integral operator
  ∪	∪	union or logical sum	union or logical sum
  ≡	≡	identical with	identical with
  ∃	∃	exists	at least one exists
  ∀	∀	for all	for all
  ƒ	ƒ	f	function of (italic small f)
  ≥	≥	>/=	greater-than-or-equal
  ∞	∞	infinity	infinity
  ∫	∫	integral	integral operator
  ∈	∈	in	set membership
  &lang;	&#x3008;	<	left angle bracket
  &lArr;	&#x21D0;	<--	is implied by
  &le;	&#x2264;	</=	less-than-or-equal
  &minus;	&#x2212;	-	minus sign
  &mnplus;	&#x2213;	-/+	minus-or-plus sign
  &nabla;	&#x2207;	nabla	del, Hamilton operator
  &ne;	&#x2260;	not equal	not equal
  &ni;	&#x220B;	contains	contains
  &or;	&#x2228;	logical or	logical or
  &par;	&#x2225;	parallel	parallel
  &part;	&#x2202;	partial differential	partial differential
  &permil;	&#x2030;	per thousand	per thousand
  &perp;	&#x22A5;	perpendicular	perpendicular
  &prime;	&#x2032;	'	prime or minute
  &Prime;	&#x2033;	''	double prime or second
  &prop;	&#x221D;	proportional, variant	is proportional to
  &radic;	&#x221A;	radical	radical
  &rang;	&#x3009;	>	right angle bracket
  &rArr;	&#x21D2;	-->	implies
  &sim;	&#x223C;	approximately	similar
  &sime;	&#x2243;	approximately	similar, equals
  &square;	&#x25A1;	square	square
  &sub;	&#x2282;	subset	subset or is implied by
  &sube;	&#x2286;	subset, dbl equals	subset, equals
  &sup;	&#x2283;	superset	superset or implies
  &supe;	&#x2287;	superset, dbl equals	superset, equals
  &there4;	&#x2234;	therefore	therefore
  &Verbar;	&#x2016;	||	double vertical bar
  &angst;	&#x212B;	A	Angstrom (capital A, ring)
  &bernou;	&#x212C;	Bernoulli function	Bernoulli function (script capital B)
  &compfn;	&#x2218;	composite function	composite function (small circle)
  &Dot;	&#x00A8;		dieresis or umlaut mark
  &DotDot;	&#x20DC;	....	four dots above
  &hamilt;	&#x210B;	H	Hamiltonian (script capital H)
  &lagran;	&#x2112;	Lgrangian	Lagrangian (script capital L)
  &lowast;	&#x2217;	*	low asterisk
  &notin;	&#x2209;	negated set membership	negated set membership
  &order;	&#x2134;	o	order of (script small o)
  &phmmat;	&#x2133;	M	physics M-matrix (script capital M)
  &tdot;	&#x20DB;	...	three dots above
  &tprime;	&#x2034;	'''	triple prime
  &wedgeq;	&#x2259;	wedge	corresponds to (wedge, equals)

  General Technical

• 

  Fractions, Super/Subscripts, Punctuation

  Fractions, Super/Subscripts, Punctuation

  ½	½	(1/2)	fraction one-half
  ½	½	(1/2)	fraction one-half
  ¼	¼	(1/4)	fraction one-quarter
  ¾	¾	(3/4)	fraction three-quarters
  ⅛	⅛	(1/8)	fraction one-eighth
  ⅜	⅜	(3/8)	fraction three-eighths
  ⅝	⅝	(5/8)	fraction five-eighths
  ⅞	⅞	(7/8)	fraction seven-eighths
  ¹	¹	(1)	superscript one
  ²	²	(2)	superscript two
  ³	³	(3)	superscript three
  +	+	+	plus sign
  ±	±	+/-	plus-or-minus sign
  &lt;	&#x003C;	<	less-than sign
  &equals;	&#x003D;	=	equals sign
  &gt;	&#x003E;	>	greater-than sign
  &divide;	&#x00F7;	/	divide sign
  &times;	&#x00D7;	x	multiply sign
  &curren;	&#x00A4;	currency	general currency sign
  &pound;	&#x00A3;	pound	pound sign
  &dollar;	&#x0024;	$	dollar sign
  &cent;	&#x00A2;	cent	cent sign
  &yen;	&#x00A5;	yen	yen sign
  &num;	&#x0023;	#	number sign
  &euro;	&#x20AC;	euro	euro sign
  &percnt;	&#x0025;	%	percent sign
  &amp;	&#x0026;	&	ampersand
  &ast;	&#x002A;	*	asterisk
  &commat;	&#x0040;	@	commercial at
  &lsqb;	&#x005B;	[	left square bracket
  &bsol;	&#x005C;	\\	reverse solidus
  &rsqb;	&#x005D;	]	right square bracket
  &lcub;	&#x007B;	{	left curly bracket
  &horbar;	&#x2015;	-	horizontal bar
  &verbar;	&#x007C;	|	vertical bar
  &rcub;	&#x007D;	}	right curly bracket
  &micro;	&#x00B5;	micro	micro sign
  &ohm;	&#x2126;	ohm	ohm sign
  &deg;	&#x00B0;	degrees	degree sign
  &ordm;	&#x00BA;	masculine	ordinal indicator, masculine
  &ordf;	&#x00AA;	feminine	ordinal indicator, feminine
  &sect;	&#x00A7;	section sign	section sign
  &para;	&#x00B6;	paragraph sign	paragraph sign
  &middot;	&#x00B7;	.	middle dot
  &larr;	&#x2190;	<--	leftward arrow
  &rarr;	&#x2192;	-->	rightward arrow
  &uarr;	&#x2191;	upward arrow	upward arrow
  &darr;	&#x2193;	downward arrow	downward arrow
  &copy;	&#x00A9;	(c)	copyright sign
  &reg;	&#x00AE;	(R)	registered sign
  &trade;	&#x2122;	trade mark	trade mark sign
  &brvbar;	&#x00A6;	|	broken (vertical) bar
  &not;	&#x00AC;	not	not sign
  &sung;	&#x266A;	music note	music note (sung text sign)
  &excl;	&#x0021;	!	exclamation mark
  &iexcl;	&#x00A1;	inverted exclamation mark	inverted exclamation mark
  &quot;	&#x0022;	"	quotation mark
  &apos;	&#x0027;	'	apostrophe
  &lpar;	&#x0028;	(	left parenthesis
  &rpar;	&#x0029;	)	right parenthesis
  &comma;	&#x002C;	,	comma
  &lowbar;	&#x005F;	_	low line
  &hyphen;	&#x2010;	-	hyphen
  &period;	&#x002E;	.	full stop, period
  &sol;	&#x002F;	/	solidus
  &colon;	&#x003A;	:	colon
  &semi;	&#x003B;	;	semicolon
  &quest;	&#x003F;	?	question mark
  &iquest;	&#x00BF;	inverted question mark	inverted question mark
  &laquo;	&#x00AB;	<<	angle quotation mark, left
  &raquo;	&#x00BB;	>>	angle quotation mark, right
  &lsquo;	&#x2018;	'	single quotation mark, left
  &rsquo;	&#x2019;	'	single quotation mark, right
  &ldquo;	&#x201C;	"	double quotation mark, left
  &rdquo;	&#x201D;	"	double quotation mark, right
  &nbsp;	&#x00A0;		no break (required) space
  &shy;	&#x00AD;	-	soft hyphen

  Fractions, Super/Subscripts, Punctuation

• 

  Greek Letters

  Greek Letters

  Entity	Unicode	PubMed Displays as	Meaning
  &agr;	α	alpha	small alpha, Greek
  &Agr;	Α	Alpha	capital Alpha, Greek
  &bgr;	β	beta	small beta, Greek
  &Bgr;	Β	Beta	capital Beta, Greek
  &ggr;	γ	gamma	small gamma, Greek
  &Ggr;	Γ	Gamma	capital Gamma, Greek
  &dgr;	δ	delta	small delta, Greek
  &Dgr;	Δ	Delta	capital Delta, Greek
  &egr;	ε	epsilon	small epsilon, Greek
  &Egr;	Ε	Epsilon	capital Epsilon, Greek
  &zgr;	ζ	zeta	small zeta, Greek
  &Zgr;	Ζ	Zeta	capital Zeta, Greek
  &eegr;	η	eta	small eta, Greek
  &EEgr;	Η	Eta	capital Eta, Greek
  &thgr;	θ	theta	small theta, Greek
  &THgr;	Θ	Theta	capital Theta, Greek
  &igr;	ι	iota	small iota, Greek
  &Igr;	Ι	Iota	capital Iota, Greek
  &kgr;	κ	kappa	small kappa, Greek
  &Kgr;	Κ	Kappa	capital Kappa, Greek
  &lgr;	λ	lambda	small lambda, Greek
  &Lgr;	Λ	Lambda	capital Lambda, Greek
  &mgr;	μ	mu	small mu, Greek
  &Mgr;	Μ	mu	capital Mu, Greek
  &ngr;	ν	nu	small nu, Greek
  &Ngr;	Ν	Nu	capital Nu, Greek
  &xgr;	ξ	xi	small xi, Greek
  &Xgr;	Ξ	Xi	capital Xi, Greek
  &ogr;	ο	omicron	small omicron, Greek
  &Ogr;	Ο	Omicron	capital Omicron, Greek
  &pgr;	π	pi	small pi, Greek
  &Pgr;	Π	Pi	capital Pi, Greek
  &rgr;	ρ	rho	small rho, Greek
  &Rgr;	Ρ	Rho	capital Rho, Greek
  &sgr;	σ	sigma	small sigma, Greek
  &Sgr;	Σ	Sigma	capital Sigma, Greek
  &sfgr;	ς	sigma	final small sigma, Greek
  &tgr;	τ	tau	small tau, Greek
  &Tgr;	Τ	Tau	capital Tau, Greek
  &ugr;	υ	upsilon	small upsilon, Greek
  &Ugr;	Υ	Upsilon	capital Upsilon, Greek
  &phgr;	φ	phi	small phi, Greek
  &PHgr;	Φ	Phi	capital Phi, Greek
  &khgr;	χ	chi	small chi, Greek
  &KHgr;	Χ	Chi	capital Chi, Greek
  &psgr;	ψ	psi	small psi, Greek
  &PSgr;	Ψ	Psi	capital Psi, Greek
  &ohgr;	ω	omega	small omega, Greek
  &OHgr;	Ω	Omega	capital Omega, Greek

  Greek Letters

• 

  Monotoniko Greek

  Monotoniko Greek

  Entity	Unicode	PubMed Displays as	Meaning
  &aacgr;	ά	alpha	small alpha, accent, Greek
  &Aacgr;	Ά	Alpha	capital Alpha, accent, Greek
  &eacgr;	έ	epsilon	small epsilon, accent, Greek
  &Eacgr;	Έ	Epsilon	capital Epsilon, accent, Greek
  &eeacgr;	ή	eta	small eta, accent, Greek
  &EEacgr;	Ή	Eta	capital Eta, accent, Greek
  &idigr;	ϊ	iota	small iota, dieresis, Greek
  &Idigr;	Ϊ	Iota	capital Iota, dieresis, Greek
  &iacgr;	ί	iota	small iota, accent, Greek
  &Iacgr;	Ί	Iota	capital Iota, accent, Greek
  &idiagr;	ΐ	iota	small iota, dieresis, accent, Greek
  &oacgr;	ό	omicron	small omicron, accent, Greek
  &Oacgr;	Ό	Omicron	capital Omicron, accent, Greek
  &udigr;	ϋ	upsilon	small upsilon, dieresis, Greek
  &Udigr;	Ϋ	Upsilon	capital Upsilon, dieresis, Greek
  &uacgr;	ύ	upsilon	small upsilon, accent, Greek
  &Uacgr;	Ύ	Upsilon	capital Upsilon, accent, Greek
  &udiagr;	ΰ	upsilon	small upsilon, dieresis, accent, Greek
  &ohacgr;	ώ	omega	small omega, accent, Greek
  &OHacgr;	Ώ	Omega	capital Omega, accent, Greek

  Monotoniko Greek

• 

  Greek Symbols

  Greek Symbols

  Entity	Unicode	PubMed Displays as	Meaning
  α	α	alpha	small alpha, Greek
  β	β	beta	small beta, Greek
  γ	γ	gamma	small gamma, Greek
  Γ	Γ	Gamma	capital Gamma, Greek
  ϝ	Ϝ	digamma	digamma
  δ	δ	delta	small delta, Greek
  Δ	Δ	Delta	capital Delta, Greek
  ε	ε	epsilon	small epsilon, Greek
  ϵ	ɛ	epsilon	var epsilon
  &epsis;	ε	epsilon	straight epsilon
  ζ	ζ	zeta	small zeta, Greek
  η	η	eta	small eta, Greek
  &thetas;	θ	theta	straight theta
  Θ	Θ	Theta	capital Theta, Greek
  ϑ	ϑ	theta	var theta - curly or open theta
  ι	ι	iota	small iota, Greek
  κ	κ	kappa	small kappa, Greek
  ϰ	ϰ	kappa	var kappa
  λ	λ	lambda	small lambda, Greek
  Λ	Λ	Lambda	capital Lambda, Greek
  μ	μ	mu	small mu, Greek
  ν	ν	nu	small nu, Greek
  ξ	ξ	xi	small xi, Greek
  Ξ	Ξ	Xi	capital Xi, Greek
  π	π	pi	small pi, Greek
  ϖ	ϖ	pi	varpi
  Π	Π	Pi	capital Pi, Greek
  ρ	ρ	rho	small rho, Greek
  ϱ	ϱ	rho	var rho
  σ	σ	sigma	small sigma, Greek
  Σ	Σ	Sigma	capital Sigma, Greek
  ς	ς	sigma	var sigma
  τ	τ	tau	small tau, Greek
  υ	υ	upsilon	small upsilon, Greek
  ϒ	ϒ	Upsilon	capital Upsilon, Greek
  &phis;	φ	phi	straight phi
  Φ	Φ	Phi	capital Phi, Greek
  ϕ	ϕ	phi	var phi - curly or open phi
  χ	χ	chi	small chi, Greek
  ψ	ψ	psi	small psi, Greek
  Ψ	Ψ	Psi	capital Psi, Greek
  ω	ω	omega	small omega, Greek
  Ω	Ω	Omega	capital Omega, Greek

  Greek Symbols

• 

  Alternative Greek Symbols

  Alternative Greek Symbols

  Entity	Unicode	PubMed Displays as	Meaning
  &b.alpha;	α	alpha	small alpha, Greek
  &b.beta;	β	beta	small beta, Greek
  &b.gamma;	γ	gamma	small gamma, Greek
  &b.Gamma;	Γ	Gamma	capital Gamma, Greek
  &b.gammad;	ϝ	digamma	digamma
  &b.delta;	δ	delta	small delta, Greek
  &b.Delta;	Δ	Delta	capital Delta, Greek
  &b.epsi;	ε	epsilon	small epsilon, Greek
  &b.epsiv;	ɛ	epsilon	var epsilon
  &b.epsis;	ε	epsilon	straight epsilon
  &b.zeta;	ζ	zeta	small zeta, Greek
  &b.eta;	η	eta	small eta, Greek
  &b.thetas;	θ	theta	straight theta
  &b.Theta;	Θ	Theta	capital Theta, Greek
  &b.thetav;	ϑ	theta	var theta - curly or open theta
  &b.iota;	ι	iota	small iota, Greek
  &b.kappa;	κ	kappa	small kappa, Greek
  &b.kappav;	ϰ	kappa	var kappa
  &b.lambda;	λ	lambda	small lambda, Greek
  &b.Lambda;	Λ	Lambda	capital Lambda, Greek
  &b.mu;	μ	mu	small mu, Greek
  &b.nu;	ν	nu	small nu, Greek
  &b.xi;	ξ	xi	small xi, Greek
  &b.Xi;	Ξ	Xi	capital Xi, Greek
  &b.pi;	π	pi	small pi, Greek
  &b.Pi;	Π	Pi	capital Pi, Greek
  &b.piv;	ϖ	pi	var pi
  &b.rho;	ρ	rho	small rho, Greek
  &b.rhov;	ϱ	rho	var rho
  &b.sigma;	σ	sigma	small sigma, Greek
  &b.Sigma;	Σ	Sigma	capital Sigma, Greek
  &b.sigmav;	ς	sigma	var sigma
  &b.tau;	τ	tau	small tau, Greek
  &b.upsi;	υ	upsilon	small upsilon, Greek
  &b.Upsi;	ϒ	Upsilon	capital Upsilon, Greek
  &b.phis;	φ	phi	straight phi
  &b.Phi;	Φ	Phi	capital Phi, Greek
  &b.phiv;	ϕ	phi	var phi - curly or open phi
  &b.chi;	χ	chi	small chi, Greek
  &b.psi;	ψ	psi	small psi, Greek
  &b.Psi;	Ψ	Psi	capital Psi, Greek
  &b.omega;	ω	omega	small omega, Greek
  &b.Omega;	Ω	Omega	capital Omega, Greek

  Alternative Greek Symbols

• 

  Relations

  Relations

  Entity	Unicode	PubMed Displays as	Meaning
  ⌉	⌉	right ceiling	right ceiling
  ⌋	⌋	right floor	right floor
  ⦔	⦔	right paren, gt	right paren, gt
  ⌝	⌝	upper right corner	upper right corner
  ⌟	⌟	downward right corner	downward right corner
  ⌈	⌈	left ceiling	left ceiling
  ⌊	⌊	left floor	left floor
  ⌜	⌜	upper left corner	upper left corner
  ⌞	⌞	downward left corner	downward left corner

  Relations

• 

  Negated Relations

  Negated Relations

  Entity	Unicode	PubMed Displays as	Meaning
  ⪈	≩	greater, not dbl equals	greater, not equals
  ≩	≩	greater, not dbl equals	greater, not double equals
  ⋧	⋧	greater, not similar	greater, not similar
  ⪉	⪉	less, not approximate	less, not approximate
  ≨	≨	less, not double equals	less, not double equals
  ⪇	≨	less, not double equals	less, not equals
  ⋦	⋦	less, not similar	less, not similar
  ≉	≉	not approximate	not approximate
  ≇	≇	not congruent with	not congruent with
  ≢	≢	not identical with	not identical with
  ≧̸	≱	not greater, double equals	not greater, double equals
  ≱	≱	not greater-than-or-equal	not greater-than-or-equal
  ⩾̸	≱	not greater, double equals	not gt-or-eq, slanted
  ≯	≯	not greater-than	not greater-than
  ≰	≰	not less-than-or-equal	not less-than-or-equal
  ≦̸	≰	not less, double equals	not less, double equals
  ⩽̸	≰	not less, double equals	not less-or-eq, slant
  ≮	≮	not less-than	not less-than
  ⋪	⋪	not left triangle	not left triangle
  ⋬	⋬	not l tri, eq	not left tri, equals
  ∤	∤	nmid	nmid
  ∦	∦	not parallel	not parallel
  ⊀	⊀	not precedes	not precedes
  ⋫	⋫	not rt triangle	not right triangle
  ⋭	⋭	not r tri, eq	not right tri, equals
  ⊁	⊁	not succeeds	not succeeds
  ≁	≁	not similar	not similar
  ≄	≄	not similar, equals	not similar, equals
  ∤	∤	nshortmid	not short mid
  ⊄	⊄	not subset	not subset
  ⊈	⊈	not subset, dbl eq	not subset, equals
  ⫅̸	⊈	not subset, dbl eq	not subset, double equals
  ⊅	⊅	not superset	not superset
  ⫆̸	⊉	not superset, equals	not superset, double equals
  ⊉	⊉	not superset, equals	not superset, equals
  ⊬	⊬	not vertical, dash	not vertical, dash
  ⊭	⊭	not vertical, dbl dash	not vertical, double dash
  ⊯	⊯	not dbl vert, dbl dash	not double vert, double dash
  ⊮	⊮	not dbl vertical, dash	not double vertical, dash
  ⪹	⋨	precedes, not approx	precedes, not approx
  ⪵	⪵	precedes, not dbl eq	precedes, not double equals
  ⋨	⋨	precedes, not approx	precedes, not similar
  ⪺	⋩	succeeds, not approx	succeeds, not approx
  ⪶	⪶	succeeds, not dbl eq	succeeds, not double equals
  ⋩	⋩	succeeds, not approx	succeeds, not similar
  ⊊	⊊	subset, not equals	subset, not equals
  ⫋	⊊	subset, not equals	subset, not double equals
  ⊋	⊋	superset, not dbl eq	superset, not equals
  ⫌	⊋	superset, not dbl eq	superset, not double equals

  Negated Relations

• 

  Arrows

  Arrows

  Entity	Unicode	PubMed Displays as	Meaning
  ↶	↶	left curved arrow	left curved arrow
  ↷	↷	right curved arrow	right curved arrow
  ⇓	⇓	down double arrow	down double arrow
  &darr2;	⇊	two down arrows	two down arrows
  ⇃	⇃	down harpoon-left	down harpoon-left
  ⇂	⇂	down harpoon-right	down harpoon-right
  ⇚	⇚	left triple arrow	left triple arrow
  ↞	↞	two head left arrow	two head left arrow
  &larr2;	⇇	two left arrows	two left arrows
  ↩	↩	left arrow-hooked	left arrow-hooked
  ↫	↫	left arrow-looped	left arrow-looped
  ↢	↢	left arrow-tailed	left arrow-tailed
  ↽	↽	left harpoon-down	left harpoon-down
  ↼	↼	left harpoon-up	left harpoon-up
  &hArr;	&#x21D4;	<-->	left&right double arrow
  &harr;	&#x2194;	<-->	left&right arrow
  &lrarr2;	&#x21C6;	left arrow over right arrow	left arrow over right arrow
  &rlarr2;	&#x21C4;	right arrow over left arrow	right arrow over left arrow
  &harrw;	&#x21AD;	left and right squig arrow	left&right arrow-wavy
  &rlhar2;	&#x21CC;	right harpoon over left harpoon	right harp over left
  &lrhar2;	&#x21CB;	left harpoon over right harpoon	left harp over right
  &lsh;	&#x21B0;	Lsh	Lsh
  &map;	&#x21A6;	mapsto	maps to
  &mumap;	&#x22B8;	multimap	multi map
  &nearr;	&#x2197;	NE pointing arrow	near pointing arrow
  &nlArr;	&#x21CD;	not implied by	not Left arrow; not implied by
  &nlarr;	&#x219A;	not left arrow	not left arrow
  &nhArr;	&#x21CE;	not l&r dbl arr	not left&right double arrow
  &nharr;	&#x21AE;	not l&r arrow	not left&right arrow
  &nrarr;	&#x219B;	not right arrow	not right arrow
  &nrArr;	&#x21CF;	not implies	not implies
  &nwarr;	&#x2196;	NW pointing arrow	NW pointing arrow
  &olarr;	&#x21BA;	left arrow in circle	left arrow in circle
  &orarr;	&#x21BB;	right arrow in circle	right arrow in circle
  &rAarr;	&#x21DB;	right triple arrow	right triple arrow
  &Rarr;	&#x21A0;	two head right arrow	two head rightarrow
  &rarr2;	&#x21C9;	two right arrows	two right arrows
  &rarrhk;	&#x21AA;	right arrow-hooked	right arrow-hooked
  &rarrlp;	&#x21AC;	right arrow-looped	right arrow-looped
  &rarrtl;	&#x21A3;	right arrow-tailed	right arrow-tailed
  &rarrw;	&#x21DD;	right arrow-wavy	right arrow-wavy
  &rhard;	&#x21C1;	right harpoon-down	right harpoon-down
  &rharu;	&#x21C0;	right harpoon-up	right harpoon-up
  &rsh;	&#x21B1;	Rsh	Rsh
  &drarr;	&#x2198;	SE pointing arrow	downward right arrow
  &dlarr;	&#x2199;	SW pointing arrow	downward left arrow
  &uArr;	&#x21D1;	up dbl arrow	up double arrow
  &uarr2;	&#x21C8;	two up arrows	two up arrows
  &vArr;	&#x21D5;	up and down dbl arrow	up&down double arrow
  &varr;	&#x2195;	up and down arrow	up&down arrow
  &uharl;	&#x21BF;	up harpoon-left	up harpoon-left
  &uharr;	&#x21BE;	up harp-right	up harp-right

  Arrows

• 

  Binary Operators

  Binary Operators

  Entity	Unicode	PubMed Displays as	Meaning
  ⌆	⌆	log and, dbl bar	logical and, double bar
  ⌅	⊼	logical and, bar above	logical and, bar above
  ⋒	⋒	dbl intersection	double intersection
  ⋓	⋓	dbl union	double union
  ⋎	⋎	curly logical or	curly logical or
  ⋏	⋏	curly logical and	curly logical and
  ⋄	⋄	open diamond	open diamond
  ⋇	⋇	division on times	division on times
  ⊺	⊺	intercal	intercal
  ⋋	⋋	leftthreetimes	left three times
  ⋉	⋉	times sign, left closed	times sign, left closed
  ⊟	⊟	minus sign in box	minus sign in box
  ⊛	⊛	asterisk in circle	asterisk in circle
  ⊚	⊚	open dot in circle	open dot in circle
  ⊝	⊝	hyphen in circle	hyphen in circle
  ⊙	⊙	middle dot in circle	middle dot in circle
  ⊖	⊖	minus sign in circle	minus sign in circle
  ⊕	⊕	plus sign in circle	plus sign in circle
  ⊘	⊘	solidus in circle	solidus in circle
  ⊗	⊗	multiply sign in circle	multiply sign in circle
  ⊞	⊞	plus sign in box	plus sign in box
  ∔	∔	plus sign, dot above	plus sign, dot above
  ⋌	⋌	rightthreetimes	right threetimes
  ⋊	⋊	times sign, right closed	times sign, right closed
  ⋅	·	.	small middle dot
  ⊡	⊡	small dot in box	small dot in box
  ∖	∖	\\	reverse solidus
  ⊓	⊓	square intersection	square intersection
  ⊔	⊔	square union	square union
  ⋆	⋆	small star, filled	small star, filled
  ⊠	⊠	multiply sign in box	multiply sign in box
  ⊤	⊤	inverted perpendicular	inverted perpendicular
  ⊎	⊎	plus sign in union	plus sign in union
  ≀	≀	wreath product	wreath product
  ◯	◯	large circle	large circle
  ▽	▽	big dn tri, open	big triangle down open
  △	△	big up tri, open	big triangle up open
  ∐	∐	coproduct operator	coproduct operator
  ∏	∏	product operator	product operator
  ∑	∑	summation operator	summation operator

  Binary Operators

• 

  Added Math Symbols - Operators

  Added Math Symbols - Operators

  Entity	Unicode	PubMed Displays as	Meaning
  ∠	∟	90 degree angle	angle
  ∡	∡	measured angle	angle-measured
  ℶ	ℶ	beth	beth, Hebrew
  ‵	‵	'	reverse prime
  ∁	∁	complement	complement sign
  ℸ	ℸ	daleth	daleth, Hebrew
  ℓ	ℓ	l	cursive small l
  ℷ	ℷ	gimel	gimel, Hebrew
  ℑ	ℑ	imaginary	imaginary
  ı	ı	i	small i, no dot
  ∄	∄	negated exists	negated exists
  Ⓢ	Ⓢ	S in circle	capital S in circle
  ℏ	ℏ	variant Planck's over 2pi	Planck's over 2pi
  ℜ	ℜ	Re	Re - real
  &sbsol;	\	\\	short reverse solidus
  &vprime;	′	'	prime, variant
  ℘	℘	Weierstrass p	Weierstrass p

  Added Math Symbols - Operators

• 

  Added Math Symbols - Relations

  Added Math Symbols - Relations

  Entity	Unicode	PubMed Displays as	Meaning
  ≊	≊	approximate, equals	approximate, equals
  ≈	≍	asymptotically equal to	asymptotically equal to
  ≌	≌	reverse congruent	reverse congruent
  ⋈	⋈	bowtie R	bowtie
  ∽	∽	reverse similar	reverse similar
  ⋍	⋍	reverse similar	reverse similar, equals
  ≎	≎	bumpy equals	bumpy equals
  ≏	≏	bumpy equals, equals	bumpy equals, equals
  ≗	≗	o=	circle, equals
  ≔	≔	:=	colon, equals
  ⋞	⋞	equal to or precedes	curly equals, precedes
  ⋟	⋟	equal to or succeeds	curly equals, succeeds
  &cupre;	≼	precedes or equal to	curly precedes, equals
  ⊣	⊣	dash, vertical	dash, vertical
  ≖	≖	circle on equals sign	circle on equals sign
  ≕	≕	=:	equals, colon
  ≑	≑	=...	equals, even dots
  ≐	≐	equals, single dot above	equals, single dot above
  ≒	≒	falling dots	equals, falling dots
  ⪖	⋝	=/>	equal-or-greater, slanted
  &els;	&#x22DC;	=/<	equals-or-less, slanted
  &erDot;	&#x2253;	rising dots	equals, rising dots
  &fork;	&#x22D4;	pitchfork	pitch fork
  &frown;	&#x2322;	down curve	down curve
  &gap;	&#x2273;	greater, similar	greater, approximate
  &gsdot;	&#x22D7;	greater than, with dot	greater than, single dot
  &gE;	&#x2267;	>==	greater, double equals
  &gel;	&#x22DB;	>=<	greater, equals, less
  &gEl;	&#x22DB;	>=<	gt, double equals, less
  &Gg;	&#x22D9;	>>>	triple gtr-than
  &gl;	&#x2277;	><	greater, less
  &gsim;	&#x2273;	greater, similar	greater, similar
  &Gt;	&#x226B;	>>	double greater-than sign
  &lap;	&#x2272;	less, similar	less, approximate
  &ldot;	&#x22D6;	less than, with dot	less than, with dot
  &lE;	&#x2266;	<==	less, double equals
  &lEg;	&#x22DA;	<=>	less, double equals, greater
  &leg;	&#x22DA;	<=>	less, equals, greater
  &lg;	&#x2276;	<>	less, greater
  &Ll;	&#x22D8;	<<<	triple less-than
  &lsim;	&#x2272;	less, similar	less, similar
  &Lt;	&#x226A;	<<	double less-than sign
  &ltrie;	&#x22B4;	left triangle, eq	left triangle, equals
  &mid;	&#x2223;	mid R:	mid
  &models;	&#x22A7;	models R:	models
  &pr;	&#x227A;	equal to or precedes	precedes
  &prap;	&#x227E;	similar	precedes, approximate
  &prsim;	&#x227E;	similar	precedes, similar
  &rtrie;	&#x22B5;	right tri, eq	right triangle , equals
  &samalg;	&#x2210;	coproduct operator	small amalg
  &sc;	&#x227B;	equal to or succeeds	succeeds
  &scap;	&#x227F;	succeeds, similar	succeeds, approximate
  &sccue;	&#x227D;	succeeds, equals	succeeds, curly equals
  &sce;	&#x227D;	succeeds, equals	succeeds, equals
  &scsim;	&#x227F;	succeeds, similar	succeeds, similar
  &sfrown;	&#x2322;	down curve	small down curve
  &smid;	&#x2223;	shortmid R:	short mid
  &smile;	&#x2323;	up curve	smile up curve
  &sqsub;	&#x228F;	square subset	square subset
  &sqsube;	&#x2291;	square subset, equals	square subset, equals
  &sqsup;	&#x2290;	square superset	square superset
  &sqsupe;	&#x2292;	square superset, eq	square superset, equals
  &ssmile;	&#x2323;	up curve	small up curve
  &Sub;	&#x22D0;	double subset	double subset
  &subE;	&#x2286;	subset, dbl equals	subset, double equals
  &Sup;	&#x22D1;	dbl superset	double superset
  &supE;	&#x2287;	superset, dbl equals	superset, double equals
  &thkap;	&#xE306;	thick approximate	thick approximate
  &thksim;	&#xE429;	thick similar	thick similar
  &trie;	&#x225C;	triangle, equals	triangle, equals
  &twixt;	&#x226C;	between	between
  &vdash;	&#x22A2;	vertical, dash	vertical, dash
  &Vdash;	&#x22A9;	dbl vertical, dash	double vertical, dash
  &vDash;	&#x22A8;	vertical, dbl dash	vertical, double dash
  &veebar;	&#x22BB;	logical or, bar below	logical or, bar below
  &vltri;	&#x22B2;	left tri, open, var	left triangle , open, var
  &vprop;	&#x221D;	proportional, variant	proportional, variant
  &vrtri;	&#x22B3;	right tri, open, var	right triangle , open, var
  &Vvdash;	&#x22AA;	triple vertical, dash	triple vertical, dash

  Added Math Symbols - Relations

• 

  Russian Cyrillic

  Russian Cyrillic

  Entity	Unicode	PubMed Displays as	Meaning
  а	а	small a, Cyrillic	small a, Cyrillic
  А	А	capital A, Cyrillic	capital A, Cyrillic
  б	б	small be, Cyrillic	small be, Cyrillic
  Б	Б	capital BE, Cyrillic	capital BE, Cyrillic
  в	в	small ve, Cyrillic	small ve, Cyrillic
  В	В	capital VE, Cyrillic	capital VE, Cyrillic
  г	г	small ghe, Cyrillic	small ghe, Cyrillic
  Г	Г	capital GHE, Cyrillic	capital GHE, Cyrillic
  д	д	small de, Cyrillic	small de, Cyrillic
  Д	Д	capital DE, Cyrillic	capital DE, Cyrillic
  е	е	small ie, Cyrillic	small ie, Cyrillic
  Е	Е	capital IE, Cyrillic	capital IE, Cyrillic
  ё	ё	small io, Russian	small io, Russian
  Ё	Ё	capital IO, Russian	capital IO, Russian
  ж	ж	small zhe, Cyrillic	small zhe, Cyrillic
  Ж	Ж	capital ZHE, Cyrillic	capital ZHE, Cyrillic
  з	з	small ze, Cyrillic	small ze, Cyrillic
  З	З	capital ZE, Cyrillic	capital ZE, Cyrillic
  и	и	small i, Cyrillic	small i, Cyrillic
  И	И	capital I, Cyrillic	capital I, Cyrillic
  й	й	small short i, Cyrillic	small short i, Cyrillic
  Й	Й	capital short I, Cyrillic	capital short I, Cyrillic
  к	к	small ka, Cyrillic	small ka, Cyrillic
  К	К	capital KA, Cyrillic	capital KA, Cyrillic
  л	л	small el, Cyrillic	small el, Cyrillic
  Л	Л	capital EL, Cyrillic	capital EL, Cyrillic
  м	м	small em, Cyrillic	small em, Cyrillic
  М	М	capital EM, Cyrillic	capital EM, Cyrillic
  н	н	small en, Cyrillic	small en, Cyrillic
  Н	Н	capital EN, Cyrillic	capital EN, Cyrillic
  о	о	small o, Cyrillic	small o, Cyrillic
  О	О	capital O, Cyrillic	capital O, Cyrillic
  п	п	small pe, Cyrillic	small pe, Cyrillic
  П	П	capital PE, Cyrillic	capital PE, Cyrillic
  р	р	small er, Cyrillic	small er, Cyrillic
  Р	Р	capital ER, Cyrillic	capital ER, Cyrillic
  с	с	small es, Cyrillic	small es, Cyrillic
  С	С	capital ES, Cyrillic	capital ES, Cyrillic
  т	т	small te, Cyrillic	small te, Cyrillic
  Т	Т	capital TE, Cyrillic	capital TE, Cyrillic
  у	у	small u, Cyrillic	small u, Cyrillic
  У	У	capital U, Cyrillic	capital U, Cyrillic
  ф	ф	small ef, Cyrillic	small ef, Cyrillic
  Ф	Ф	capital EF, Cyrillic	capital EF, Cyrillic
  х	х	small ha, Cyrillic	small ha, Cyrillic
  Х	Х	capital HA, Cyrillic	capital HA, Cyrillic
  ц	ц	small tse, Cyrillic	small tse, Cyrillic
  Ц	Ц	capital TSE, Cyrillic	capital TSE, Cyrillic
  ч	ч	small che, Cyrillic	small che, Cyrillic
  Ч	Ч	capital CHE, Cyrillic	capital CHE, Cyrillic
  ш	ш	small sha, Cyrillic	small sha, Cyrillic
  Ш	Ш	capital SHA, Cyrillic	capital SHA, Cyrillic
  щ	щ	small shcha, Cyrillic	small shcha, Cyrillic
  Щ	Щ	capital SHCHA, Cyrillic	capital SHCHA, Cyrillic
  ъ	ъ	small hard sign, Cyrillic	small hard sign, Cyrillic
  Ъ	Ъ	capital HARD sign, Cyrillic	capital HARD sign, Cyrillic
  ы	ы	small yeru, Cyrillic	small yeru, Cyrillic
  Ы	Ы	capital YERU, Cyrillic	capital YERU, Cyrillic
  ь	ь	small soft sign, Cyrillic	small soft sign, Cyrillic
  Ь	Ь	capital SOFT sign, Cyrillic	capital SOFT sign, Cyrillic
  э	э	small e, Cyrillic	small e, Cyrillic
  Э	Э	capital E, Cyrillic	capital E, Cyrillic
  ю	ю	small yu, Cyrillic	small yu, Cyrillic
  Ю	Ю	capital YU, Cyrillic	capital YU, Cyrillic
  я	я	small ya, Cyrillic	small ya, Cyrillic
  Я	Я	capital YA, Cyrillic	capital YA, Cyrillic
  №	№	numero sign	numero sign

  Russian Cyrillic

• 

  Non-Russian Cyrillic

  Non-Russian Cyrillic

  Entity	Unicode	PubMed Displays as	Meaning
  ђ	ђ	small dje, Serbian	small dje, Serbian
  Ђ	Ђ	capital DJE, Serbian	capital DJE, Serbian
  ѓ	ѓ	small gje, Macedonian	small gje, Macedonian
  Ѓ	Ѓ	capital GJE Macedonian	capital GJE Macedonian
  є	є	small je, Ukrainian	small je, Ukrainian
  Є	Є	capital JE, Ukrainian	capital JE, Ukrainian
  ѕ	ѕ	small dse, Macedonian	small dse, Macedonian
  Ѕ	Ѕ	capital DSE, Macedonian	capital DSE, Macedonian
  і	і	small i, Ukrainian	small i, Ukrainian
  І	І	capital I, Ukrainian	capital I, Ukrainian
  ї	ї	small yi, Ukrainian	small yi, Ukrainian
  Ї	Ї	capital YI, Ukrainian	capital YI, Ukrainian
  ј	ј	small je, Serbian	small je, Serbian
  Ј	Ј	capital JE, Serbian	capital JE, Serbian
  љ	љ	small lje, Serbian	small lje, Serbian
  Љ	Љ	capital LJE, Serbian	capital LJE, Serbian
  њ	њ	small nje, Serbian	small nje, Serbian
  Њ	Њ	capital NJE, Serbian	capital NJE, Serbian
  ћ	ћ	small tshe, Serbian	small tshe, Serbian
  Ћ	Ћ	capital TSHE, Serbian	capital TSHE, Serbian
  ќ	ќ	small kje Macedonian	small kje Macedonian
  Ќ	Ќ	capital KJE, Macedonian	capital KJE, Macedonian
  ў	ў	small u, Byelorussian	small u, Byelorussian
  Ў	Ў	capital U, Byelorussian	capital U, Byelorussian
  џ	џ	small dze, Serbian	small dze, Serbian
  Џ	Џ	capital dze, Serbian	capital dze, Serbian

  Non-Russian Cyrillic

• 

  Box and Line Drawing

  Box and Line Drawing

  Entity	Unicode	PubMed Displays as	Meaning
  ─	─	horizontal line	horizontal line
  │	│	vertical line	vertical line
  └	└	upper right quadrant	upper right quadrant
  ┘	┘	upper left quadrant	upper left quadrant
  ┐	┐	lower left quadrant	lower left quadrant
  ┌	┌	lower right quadrant	lower right quadrant
  ├	├	upper and lower right quadrants	upper and lower right quadrants
  ┴	┴	upper left and right quadrants	upper left and right quadrants
  ┤	┤	upper and lower left quadrants	upper and lower left quadrants
  ┬	┬	lower left and right quadrants	lower left and right quadrants
  ┼	┼	all four quadrants	all four quadrants
  ╞	╞	upper and lower right quadrants	upper and lower right quadrants
  ╨	╨	upper left and right quadrants	upper left and right quadrants
  ╡	╡	upper and lower left quadrants	upper and lower left quadrants
  ╥	╥	lower left and right quadrants	lower left and right quadrants
  ╪	╪	all four quadrants	all four quadrants
  ═	═	horizontal line	horizontal line
  ║	║	vertical line	vertical line
  ╚	╚	upper right quadrant	upper right quadrant
  ╝	╝	upper left quadrant	upper left quadrant
  ╗	╗	lower left quadrant	lower left quadrant
  ╔	╔	lower right quadrant	lower right quadrant
  ╠	╠	upper and lower right quadrants	upper and lower right quadrants
  ╩	╩	upper left and right quadrants	upper left and right quadrants
  ╣	╣	upper and lower left quadrants	upper and lower left quadrants
  ╦	╦	lower left and right quadrants	lower left and right quadrants
  ╬	╬	all four quadrants	all four quadrants
  ╟	╟	upper and lower right quadrants	upper and lower right quadrants
  ╧	╧	upper left and right quadrants	upper left and right quadrants
  ╢	╢	upper and lower left quadrants	upper and lower left quadrants
  ╤	╤	lower left and right quadrants	lower left and right quadrants
  ╫	╫	all four quadrants	all four quadrants
  ╘	╘	upper right quadrant	upper right quadrant
  ╜	╜	upper left quadrant	upper left quadrant
  ╕	╕	lower left quadrant	lower left quadrant
  ╓	╓	lower right quadrant	lower right quadrant
  ╙	╙	upper right quadrant	upper right quadrant
  ╛	╛	upper left quadrant	upper left quadrant
  ╖	╖	lower left quadrant	lower left quadrant
  ╒	╒	lower right quadrant	lower right quadrant

  Box and Line Drawing

Correcting Errors in PubMed

An error found in a PubMed record can be corrected, but whether the correction can be made by the publisher depends on the publication status of the citation in question and whether the error also occurred in the original version of the article (print or online).

Publishers can correct errors ONLY if the citation has the publication status [PubMed - as supplied by publisher]. Citations with the publication status [PubMed - in process], [PubMed - Indexed for MEDLINE], [PubMed] and [PubMed - OLDMEDLINE] can ONLY be corrected by NLM staff.

Errors that also appeared in the original version of the article cannot be corrected until an Erratum is issued in an upcoming issue of the journal. Please see NLM's Errata, Retraction, Duplicate Publication, and Comment Policy Fact Sheet for more information.

Instructions for articles published in Non-English Languages

Here is an example of a non-English language citation:

The [brackets] around the article title and the text "French" indicate the full-text of the article is in a language other than English. The French article title can be viewed by selecting the XML display for this citation in PubMed.

Publishers submitting files for articles published in non-English languages often have specific questions about how to construct their XML files. Here are some guidelines for the submission of non-English articles. We also have a sample XML file for this type of article.

All About Ahead of Print

Publishers who are authorized to submit XML data to PubMed have the option of submitting citations prior to their publication in final or print format. This option is used for those publications in which the date of an article's electronic publishing predates publication in the journal issue or volume. When articles are first made available on a Web site (publishers’ or other), the publisher or provider sends the same citation data made available to the public for inclusion in PubMed.

Often these types of citations contain partial citation information--for example, they might contain an article title and full abstract, but not contain a volume, issue, or page number. This information is expected to be filled in by a Replaces XML file after the issue or volume has been finalized or printed. These incomplete citation records hold an [Epub ahead of print] status until updated data is sent to PubMed. See our Ahead of Print File Example and the Replacement File that updates it.

IMPORTANT: The Ahead of Print (AOP) mechanism must not be used for an article if its eventual publication is uncertain. In the rare case where an AOP citation is retracted, the citation information should remain on the publisher Web site. See our Ahead of Print Withdrawn policy

Here's an example of an AOP citation in PubMed:

The notation [Epub ahead of print] labels this citation as incomplete. Note it does not display a volume number or issue number or page numbers, only a publication date.

Here's the same citation after being updated with a Replacement File:

Instructions for Replacement Files

Replacement Files can be used for two purposes: updating an Ahead of Print (AOP) citation or correcting a citation currently in [PubMed - as supplied by publisher] status.

AOP citations eventually become "published" citations by way of the publisher sending a Replacement XML file with completed citation information. These replacement files must use the PubStatus attribute value "ppublish" or "epublish" in the <PubDate> tag in order to replace the AOP citation.

Take the following steps to update an AOP citation:

• Update the AOP citation file, adding the finalized citation information.

• Add the final publication date to the <PubDate> tag, along with the PubStatus="ppublish" or "epublish" attribute. The publication date must be exactly as it appears on the finalized article. See "How should the Publication Date be submitted?"

• "Move" the existing PubDate with PubStatus="aheadofprint" attribute to the <History> tag. This will enable the citation to retain the AOP publishing date in PubMed.

• Add a single <Replaces> tag to each <Article> to be updated. The <Replaces> tags should be placed after the <Journal> tags and before the <ArticleTitle> tags, and should contain the IdType attribute with one of the following values: "pubmed" (default), "pii", "doi" of the citation to be updated. The PubMed ID (PMID) can be located in the Loader Report or by searching for the article in PubMed.

• Verify that the ArticleIdList (pii or doi) in the Replacement File matches the ArticleIdList in the AOP citation in PubMed. If these numbers do not match, the citation will not be updated.

• Check the file for errors and preview the PubMed Abstract display using the PubMed Citation XML File Validator.

• FTP the Replacement File to your private ftp account, placing it at the top of the directory.

• Wait for a Loader Report confirming the loading of the Replacement File. Following the batch of articles is a "Total processed" message indicating the number of articles processed from the uploaded file and the number created, replaced, and rejected.

For additional reference, see our Ahead of Print File Example and the Replacement File that updates it.

Ahead of Print Withdrawn Policy

On rare occasions a publisher may need to remove an Ahead of Print (AOP) article from a journals’ Web site. There are a variety of reasons for this type of withdrawal; plagiarism, copyright infringements, duplicate publication in another journal. PubMed understands that these circumstances cannot always be prevented before AOP citation data is uploaded to PubMed. Thus we have designed the following policy:

If an AOP article is removed completely from the journals’ Web site the publisher should have a Replacement file uploaded to PubMed. The Replacement file should use the following format:
The text "WITHDRAWN:" (without quotation marks) should appear at the beginning of the original article title in the <ArticleTitle> tag.

The text "Ahead of Print article withdrawn by publisher." (without quotation marks) should be added at the beginning of the original text within the <Abstract> tag. If desired the original abstract text may be completely replaced with the above text. For additional reference, see our Instructions for Replacement Files.

Here's an example:

If an AOP article is replaced on the journals’ Web site with a Retraction or Withdrawn Notice then the publisher should have a Replacement file uploaded to PubMed. The Replacement file should match the text of the Retraction or Withdrawn Notice on the journal's Web site.

Here's an example: