Editing Alphabetical order

{{Short description|System for ordering words, names and phrases}}
{{redirect2|Alphabetical|Alphabetization|other uses|Alphabetical (disambiguation)|the creation of an alphabetic writing system, which in instances of Latin script is called romanization|Romanization}}
{{Use dmy dates|date=June 2017}}

[[File:Paris Summit for the Support to the Libyan People 01.jpg|thumb|upright=1.3|Flags of certain countries at the [[Élysée Palace]] in Paris for a peace conference regarding Libya, 2011. The national flags (other than that of the host, France) are arranged in French alphabetical order: ''Allemagne'', ''Belgique'', ''Canada'', ''Danemark'', ''Émirats Arabes Unis'', ''Espagne'', ''États-Unis'', ''Grèce'', ''Irak'', ''Italie'', ''Jordanie'', ''Maroc'', ''Norvège'', ''Pays-Bas'', ''Pologne'', ''Qatar'', ''Royaume-Uni''.]]
'''Alphabetical order''' is a system whereby [[character string]]s are placed in order based on the position of the characters in the conventional ordering of an [[alphabet]]. It is one of the methods of [[collation]]. In mathematics, a [[lexicographical order]] is the generalization of the alphabetical order to other data types, such as [[sequence (mathematics)|sequences]] of numbers or other ordered [[mathematical object]]s.

When applied to strings or [[sequence (mathematics)|sequences]] that may contain digits, numbers or more elaborate types of elements, in addition to alphabetical characters, the alphabetical order is generally called a [[lexicographical order]].

To determine which of two strings of characters comes first when arranging in alphabetical order, their first [[letter (alphabet)|letters]] are compared. If they differ, then the string whose first letter comes earlier in the alphabet comes before the other string. If the first letters are the same, then the second letters are compared, and so on. If a position is reached where one string has no more letters to compare while the other does, then the first (shorter) string is deemed to come first in alphabetical order.

[[Capital letter|Capital or upper case]] letters are generally considered to be identical to their corresponding lower case letters for the purposes of alphabetical ordering, although conventions may be adopted to handle situations where two strings differ only in capitalization. Various conventions also exist for the handling of strings containing [[space (symbol)|space]]s, modified letters, such as those with [[diacritic]]s, and non-letter characters such as marks of [[punctuation]].

The result of placing a set of words or strings in alphabetical order is that all of the strings beginning with the same letter are grouped together; within that grouping all words beginning with the same two-letter sequence are grouped together; and so on. The system thus tends to maximize the number of common initial letters between adjacent words.

==History==
The order of the letters of the alphabet is attested from the 14th century&nbsp;BC in the town of [[Ugarit]] on [[Syria]]'s northern coast.<ref>{{Cite book |last=Robinson |first=Andrew |title=The story of writing |publisher=Thames & Hudson |year=2007 |isbn=978-0-500-28660-9 |edition=2nd |location=London |orig-date=1995|p=162}}</ref> Tablets found there bear over one thousand cuneiform signs, but these signs are not Babylonian and there are only thirty distinct characters. About twelve of the tablets have the signs set out in alphabetic order. There are two orders found, one of which is nearly identical to the order used for [[Hebrew alphabet|Hebrew]], [[Greek alphabet|Greek]] and [[Latin alphabet|Latin]], and a second order very similar to that used for [[Geʽez script|Geʽez]].<ref>{{Cite journal |last=Millard |first=A. R. |year=1986 |title=The infancy of the alphabet |journal=World Archaeology |volume=17 |issue=3 |pages=390–398 |doi=10.1080/00438243.1986.9979978 |jstor=124703}}</ref>

It is not known how many letters the [[Proto-Sinaitic alphabet]] had nor what their alphabetic order was. Among its descendants, the [[Ugaritic alphabet]] had 27 consonants, the [[South Arabian alphabet]]s had 29, and the [[Phoenician alphabet]] 22. These scripts were arranged in two orders, an ''ABGDE'' order in Phoenician and an ''HMĦLQ'' order in the south; Ugaritic preserved both orders. Both sequences proved remarkably stable among the descendants of these scripts.

As applied to words, alphabetical order was first used in the 1st millennium [[BCE]] by Northwest Semitic scribes using the [[abjad]] system.<ref>Reinhard G. Lehmann: "27-30-22-26. How Many Letters Needs an Alphabet? The Case of Semitic", in: ''The idea of writing: Writing across borders'', edited by Alex de Voogt and Joachim Friedrich Quack, Leiden: Brill 2012, pp. 11–52.</ref> However, a range of other methods of classifying and ordering material, including geographical, [[chronological]], [[hierarchical]] and [[Categorization|by category]], were preferred over alphabetical order for centuries.<ref name=atoz/>

Parts of the [[Bible]] are dated to the 7th–6th centuries BCE. In the [[Book of Jeremiah]], the prophet utilizes the [[Atbash]] [[substitution cipher]], based on alphabetical order. Similarly, biblical authors used [[acrostic]]s based on the (ordered) [[Hebrew alphabet]].<ref>e.g. Psalms 25, 34, 37, 111, 112, 119 and 145 of the Hebrew Bible</ref>

The first effective use of alphabetical order as a cataloging device among scholars may have been in ancient Alexandria,<ref>Daly, Lloyd. ''Contributions to the History of Alphabetization in Antiquity and the Middle Ages''. Brussels, 1967. p. 25.</ref> in the [[Great Library of Alexandria]], which was founded around 300 BCE. The poet and scholar [[Callimachus]], who worked there, is thought to have created the world's first [[library catalog]], known as the [[Pinakes]], with scrolls shelved in alphabetical order of the first letter of authors' names.<ref name=atoz>{{cite web | title=From A to Z - the surprising history of alphabetical order | website=ABC News (ABC Radio National) | format=text and audio | first=Julie | last=Street | publisher=Australian Broadcasting Corporation | date=10 June 2020 | url=https://www.abc.net.au/news/2020-06-11/history-of-alphabetical-order-a-to-z/12320808 | access-date=6 July 2020 | archive-date=2 July 2020 | archive-url=https://web.archive.org/web/20200702080945/https://www.abc.net.au/news/2020-06-11/history-of-alphabetical-order-a-to-z/12320808 | url-status=live }}</ref>

In the 1st century BC, Roman writer [[Varro]] compiled alphabetic lists of authors and titles.<ref name="O'Hara">{{cite journal |title=Messapus, Cycnus, and the Alphabetical Order of Vergil's Catalogue of Italian Heroes |last=O'Hara |first=James |journal=Phoenix |year=1989 |jstor=1088539 |volume=43 |issue=1 |pages=35–38|doi=10.2307/1088539 }}</ref> In the 2nd century CE, [[Sextus Pompeius Festus]] wrote an encyclopedic [[epitome]] of the works of [[Verrius Flaccus]], ''[[De verborum significatu]]'', with entries in alphabetic order.<ref name="remacle">{{cite book |url=http://remacle.org/bloodwolf/erudits/Festus/m.htm |title=LIVRE XI – texte latin – traduction + commentaires |access-date=8 May 2012 |archive-date=9 June 2012 |archive-url=https://web.archive.org/web/20120609075646/http://remacle.org/bloodwolf/erudits/Festus/m.htm |url-status=live }}</ref> In the 3rd century CE, [[Harpocration]] wrote a [[Homer]]ic lexicon alphabetized by all letters.<ref name="gibson">{{cite book |title=Interpreting a classic: Demosthenes and his ancient commentators |last=Gibson |first=Craig |year=2002 }}</ref> 

The 10th century saw major alphabetical lexicons of Greek (the ''[[Suda]]''), Arabic ([[Ibn Faris]]'s ''al-Mujmal fī al-Lugha''), and [[Biblical Hebrew]] ([[Menahem ben Saruq]]'s ''Mahberet''). Alphabetical order as an aid to consultation flourished in 11th-century Italy, which contributed works on Latin ([[Papias (lexicographer)|Papias]]'s ''Elementarium'') and [[Jewish Babylonian Aramaic|Talmudic Aramaic]] ([[Nathan ben Jehiel]]'s ''Arukh'').{{Efn|Nathan's ''Arukh'' may not have been the first alphabetical Talmudic dictionary, but it achieved surpassing popularity and remains in use today. One possible antecedent is the lost ''Alpha-Beta'' of {{ill|Machir ben Yehuda|he|מכיר בן יהודה}}.}} 

In the second half of the 12th century, [[preachers|Christian preachers]] adopted alphabetical tools to analyse [[Bible|biblical]] vocabulary. This led to the compilation of alphabetical [[Concordance (publishing)|concordances]] of the Bible by the [[Dominican friars]] in [[Paris]] in the 13th century, under [[Hugh of Saint Cher]]. Older reference works such as [[St. Jerome]]'s ''Interpretations of Hebrew Names'' were alphabetized for ease of consultation. The use of alphabetical order was initially resisted by scholars, who expected their students to master their area of study according to its own rational structures; its success was driven by such tools as [[Robert Kilwardby]]'s index to the works of [[St. Augustine]], which helped readers access the full original text instead of depending on the compilations of [[Quotation|excerpts]] which had become prominent in 12th century [[scholasticism]]. The adoption of alphabetical order was part of the transition from the primacy of [[memory]] to that of written works.<ref name="Rouse">{{citation |last1 = Rouse |first1 = Mary A. |last2 = Rouse |first2 = Richard M. |contribution = ''Statim invenire'': Schools, Preachers and New Attitudes to the Page |title = Authentic Witnesses: Approaches to Medieval Texts and Manuscripts |pages = 201–219 |publisher = University of Notre Dame Press |year = 1991 |isbn = 0-268-00622-9 }}</ref> The idea of ordering information by the order of the alphabet also met resistance from the compilers of encyclopaedias in the 12th and 13th centuries, who were all devout churchmen. They preferred to organise their material [[theologically]] – in the order of God's creation, starting with ''Deus'' (meaning God).<ref name="atoz" />

In 1604 [[Robert Cawdrey]] had to explain in ''[[Table Alphabeticall]]'', the first [[monolingual]] English [[dictionary]], "Nowe if the word, which thou art desirous to finde, begin with (a) then looke in the beginning of this Table, but if with (v) looke towards the end".<ref name=Cawdrey>{{cite book |first=Robert |last=Cawdrey |title=A Table Alphabeticall |location=London |year=1604 |page=[A4]v }}</ref> Although as late as 1803 [[Samuel Taylor Coleridge]] condemned encyclopedias with "an arrangement determined by the accident of initial letters",<ref name="Coleridge">{{cite book |url=https://www.inamidst.com/coleridge/letters/letter507 |title=Coleridge's Letters, No.507}}</ref> many lists are today based on this principle.

==Ordering in the Latin script==

===Basic order and examples===
The standard order of the modern [[ISO basic Latin alphabet]] is:
:'''A-B-C-D-E-F-G-H-I-J-K-L-M-N-O-P-Q-R-S-T-U-V-W-X-Y-Z'''

An example of straightforward alphabetical ordering follows:
*'''''As; Aster; Astrolabe; Astronomy; Astrophysics; At; Ataman; Attack; Baa'''''
Another example:
*'''''Barnacle; Be; Been; Benefit; Bent'''''
 
The above words are ordered alphabetically. ''As'' comes before ''Aster'' because they begin with the same two letters and ''As'' has no more letters after that whereas ''Aster'' does. The next three words come after ''Aster'' because their fourth letter (the first one that differs) is ''r'', which comes after ''e'' (the fourth letter of ''Aster'') in the alphabet. Those words themselves are ordered based on their sixth letters (''l'', ''n'' and ''p'' respectively). Then comes ''At'', which differs from the preceding words in the second letter (''t'' comes after ''s''). ''Ataman'' comes after ''At'' for the same reason that ''Aster'' came after ''As''. ''Attack'' follows ''Ataman'' based on comparison of their third letters, and ''Baa'' comes after all of the others because it has a different first letter.

===Treatment of multiword strings===
When some of the strings being ordered consist of more than one word, i.e., they contain [[space (character)|spaces]] or other separators such as [[hyphen]]s, then two basic approaches may be taken. In the first approach, all strings are ordered initially according to their first word, as in the sequence:
*''Oak; Oak Hill; Oak Ridge; Oakley Park; Oakley River''
*:where all strings beginning with the separate word ''Oak'' precede all those beginning with ''Oakley'', because ''Oak'' precedes ''Oakley'' in alphabetical order.

In the second approach, strings are alphabetized as if they had no spaces or hyphens,{{efn|In MS Explorer's case, the space, the apostrophe (U+0027), and all of the hyphen-like characters (U+002D and U+2010 through U+2014, inclusive) are omitted from the primary sort key.}} giving the sequence:
*''Oak; Oak Hill; Oakley Park; Oakley River; Oak Ridge''
*:where ''Oak Ridge'' now comes after the ''Oakley'' strings, as it would if it were written "Oakridge".

The second approach is the one usually taken in dictionaries,{{citation needed|date=October 2020}} and it is thus often called ''[[dictionary order (disambiguation)|dictionary order]]'' by [[publishing|publishers]].{{efn|For instance, the ''Harrap's Shorter Dictionnaire Anglais-Français/ Français-Anglais'', ISBN 0-245-60660-2, page 640, has the ordering ''oil, oil-bearing, oilcan, oilcloth, oil-cooled, oiled ''[…]'' oiliness, oil lamp, oil paint, oil painting, oilpaper''.}} The first approach has often been used in [[index (publishing)|book indexes]], although each publisher traditionally set its own standards for which approach to use therein; there was no ISO standard for book indexes ([[ISO 999]]) before 1975.

===Special cases===
{{Unreferenced section|date=June 2017}}

====Modified letters====
In French, modified letters (such as those with [[diacritic]]s) are treated the same as the base letter for alphabetical ordering purposes. For example, ''rôle'' comes between ''rock'' and ''rose'', as if it were written ''role''. However, languages that use such letters systematically generally have their own ordering rules. See {{slink||Language-specific conventions}} below.

====Ordering by surname====
In most cultures where [[family name]]s are written after [[given name]]s, it is still desired to sort lists of names (as in telephone directories) by family name first. In this case, names need to be reordered to be sorted correctly. For example, Juan Hernandes and Brian O'Leary should be sorted as "Hernandes, Juan" and "O'Leary, Brian" even if they are not written this way. Capturing this rule in a computer collation algorithm is complex, and simple attempts will fail. For example, unless the algorithm has at its disposal an extensive list of family names, there is no way to decide if "Gillian Lucille van der Waal" is "van der Waal, Gillian Lucille", "Waal, Gillian Lucille van der", or even "Lucille van der Waal, Gillian".

Ordering by surname is frequently encountered in academic contexts. Within a single multi-author paper, ordering the authors alphabetically by surname, rather than by other methods such as reverse seniority or subjective degree of contribution to the paper, is seen as a way of "acknowledg[ing] similar contributions" or "avoid[ing] disharmony in collaborating groups".<ref>{{cite journal|first1=Teja|last1=Tscharntke|first2=Michael E|last2=Hochberg|first3=Tatyana A|last3=Rand|first4=Vincent H|last4=Resh|first5=Jochen|last5=Krauss|title=Author Sequence and Credit for Contributions in Multiauthored Publications|journal=PLOS Biol.|date=January 2007|volume=5|issue=1|pages=e18|pmid=17227141|doi=10.1371/journal.pbio.0050018|pmc=1769438 |doi-access=free }}</ref> The practice in certain fields of ordering [[citation]]s in bibliographies by the surnames of their authors has been found to create bias in favour of authors with surnames which appear earlier in the alphabet, while this effect does not appear in fields in which bibliographies are ordered chronologically.<ref>{{cite journal|url=https://decisionslab.unl.edu/pubs/stevens_duque_2018_SM.pdf|first1=Jeffrey R.|last1=Stevens|first2=Juan F.|last2=Duque|title=Order Matters: Alphabetizing In-Text Citations Biases Citation Rates|journal=Psychonomic Bulletin & Review|year=2018|volume=26|issue=3|pages=1020–1026|doi=10.3758/s13423-018-1532-8|doi-access=free|pmid=30288671|s2cid=52922399|access-date=10 November 2018|archive-date=10 November 2018|archive-url=https://web.archive.org/web/20181110080311/https://decisionslab.unl.edu/pubs/stevens_duque_2018_SM.pdf|url-status=live}}
*{{lay source |author=Colleen Flaherty |title=The Case Against Alphabetical Naming of Authors |url=https://www.insidehighered.com/news/2018/10/22/study-takes-aim-psychologys-practice-ordering-reference-lists-alphabetically|website=[[Inside Higher Ed]] |date=22 October 2018}}</ref>

====''The'' and other common words====
If a phrase begins with a very common word (such as "the", "a" or "an", called articles in grammar), that word is sometimes ignored or moved to the end of the phrase, but this is not always the case. For example, the book "[[The Shining (novel)|The Shining]]" might be treated as "Shining", or "Shining, The" and therefore before the book title "[[Summer of Sam]]". However, it may also be treated as simply "The Shining" and after "Summer of Sam". Similarly, "[[A Wrinkle in Time]]" might be treated as "Wrinkle in Time", "Wrinkle in Time, A", or "A Wrinkle in Time". All three alphabetization methods are fairly easy to create by algorithm, but many programs rely on simple [[lexicographic order]]ing instead.

====''Mac'' prefixes====
{{Main|Mac and Mc together}}
The prefixes ''M'' and ''Mc'' in Irish and Scottish surnames are abbreviations for ''Mac'' and are sometimes alphabetized as if the spelling is ''Mac'' in full. Thus ''McKinley'' might be listed before ''Mackintosh'' (as it would be if it had been spelled out as "MacKinley"). Since the advent of computer-sorted lists, this type of alphabetization is less frequently encountered, though it is still used in British telephone directories.

====''St'' prefix====
The prefix ''St'' or ''St.'' is an abbreviation of "Saint", and is traditionally alphabetized as if the spelling is ''Saint'' in full. Thus in a gazetteer ''St John's'' might be listed before ''Salem'' (as if it would be if it had been spelled out as "Saint John's"). Since the advent of computer-sorted lists, this type of alphabetization is less frequently encountered, though it is still sometimes used.

====Ligatures====
[[Typographic ligature|Ligatures]] (two or more letters merged into one symbol) which are not considered distinct letters, such as [[Æ]] and [[Œ]] in English, are typically collated as if the letters were separate—"æther" and "aether" would be ordered the same relative to all other words. This is true even when the ligature is not purely stylistic, such as in [[loanword]]s and brand names.

Special rules may need to be adopted to sort strings which vary only by whether two letters are joined by a ligature.

===Treatment of numerals===
{{Main|Lexicographical order}}
{{Unreferenced section|date=June 2017}}

When some of the strings contain [[Numerical digit|numeral]]s (or other non-letter characters), various approaches are possible. Sometimes such characters are treated as if they came before or after all the letters of the alphabet. Another method is for numbers to be sorted alphabetically as they would be spelled: for example ''[[1776 (film)|1776]]'' would be sorted as if spelled out "seventeen seventy-six", and {{Lang|fr|[[24 heures du Mans]]}} as if spelled "vingt-quatre..." (French for "twenty-four"). When numerals or other symbols are used as special graphical forms of letters, as ''1337'' for [[leet]] or the movie ''[[Seven (1995 film)|Seven]]'' (which was stylised as ''Se7en''), they may be sorted as if they were those letters. [[Natural sort order]] orders strings alphabetically, except that multi-digit numbers are treated as a single character and ordered by the value of the number encoded by the digits.

In the case of [[monarch]]s and [[pope]]s, although their numbers are in [[Roman numerals]] and resemble letters, they are normally arranged in numerical order: so, for example, even though V comes after I, the Danish king [[Christian IX of Denmark|Christian IX]] comes after his predecessor [[Christian VIII of Denmark|Christian VIII]].

===Language-specific conventions===
{{more citations needed|section|date=June 2017}}
Languages which use an [[extended Latin alphabet]] generally have their own conventions for treatment of the extra letters. Also in some languages certain [[digraph (orthography)|digraph]]s are treated as single letters for collation purposes. For example, the [[Spanish orthography|Spanish alphabet]] treats ''ñ'' as a basic letter following ''n'', and formerly treated the digraphs ''ch'' and ''ll'' as basic letters following ''c'' and ''l'', respectively. Now ''ch'' and ''ll'' are alphabetized as two-letter combinations. The new alphabetization rule was issued by the [[Royal Spanish Academy]] in 1994. These digraphs were  still formally designated as letters but they are no longer so since 2010. On the other hand, the digraph ''rr'' follows ''rqu'' as expected (and did so even before the 1994 alphabetization rule), while vowels with acute accents (''á, é, í, ó, ú'') have always been ordered in parallel with their base letters, as has the letter ''ü''.

In a few cases, such as [[Arabic alphabet|Arabic]] and [[Kiowa alphabet|Kiowa]], the alphabet has been completely reordered.

Alphabetization rules applied in various languages are listed below.
* In [[Arabic Language|Arabic]], there are two main orders of the [[Arabic alphabet|28 letter alphabet]] used today. The standard and most commonly used is the ''[[Arabic alphabet#hijāʾī|hijāʾī]]'' order, which was created by the early Arab linguist [[Nasr ibn 'Asim al-Laythi]] and features a visual ordering method where letters are ordered based on their shapes. For example ''bāʾ'' (ب), ''tāʾ'' (ت), ''thāʾ'' (ث) are grouped as they have the same base shape or ''[[rasm]]'' (ٮ) and are differentiated only by consonant pointing known as ''[[Arabic diacritics#I‘jām (phonetic distinctions of consonants)|iʻjām]]''. The original ''[[Arabic alphabet#Abjadi|ʾabjadī]]'' order, which phonetically resembles that of other [[Semitic languages]] as well as Latin, is still in use today, usually limited for ordering lists in a document, analogous to [[Roman Numerals]]. When the ''ʾabjadī'' order is used in numbering, letters are written in a modified form to distinguish them from letters used in words and from numerals. For example, ''ʾalif'' (ا) which looks identical to the [[Eastern Arabic numeral]] one (١), a small oval loop extends clockwise of the letter's bottom, followed by a short tail (𞺀).{{cn|date=August 2024}} Although these characters are rarely used digitally they are encoded in Unicode under [[Arabic Mathematical Alphabetic Symbols]].<ref>{{cite web |title=Arabic Mathematical Alphabetic Symbols |url=https://www.unicode.org/charts/PDF/U1EE00.pdf |publisher=THE Unicode Standard |access-date=26 November 2022 |archive-date=30 October 2022 |archive-url=https://web.archive.org/web/20221030230610/https://www.unicode.org/charts/PDF/U1EE00.pdf |url-status=live }}</ref> A less common order, the ''{{ill|ṣawtī|ar|ترتيب_صوتي|v=sup}}'' order, is collated phonetically and was created by [[al-Khalil ibn Ahmad al-Farahidi]].
* In [[Azerbaijani language|Azerbaijani]], there are eight additional letters to the standard Latin alphabet. Five of them are vowels: i, ı, ö, ü, [[ə]] and three are consonants: ç, ş, ğ. The alphabet is the same as the [[Turkish alphabet|Turkish]], with the same sounds written with the same letters, except for three additional letters: q, x and ə for sounds that do not exist in Turkish. Although all the "Turkish letters" are collated in their "normal" alphabetical order like in Turkish, the three extra letters are collated arbitrarily after letters whose sounds approach theirs. So, q is collated just after k, x (pronounced like a German ''ch'') is collated just after h and ə (pronounced roughly like an English short ''a'') is collated just after e.
* In [[Breton language|Breton]], there is no "c", "q", "x" but there are the digraphs "ch" and "c'h", which are collated between "b" and "d". For example: «&nbsp;buzhugenn, chug, c'hoar, daeraouenn&nbsp;» (earthworm, juice, sister, teardrop).
* In [[Czech language|Czech]] and [[Slovak language|Slovak]], accented vowels have secondary collating weight – compared to other letters, they are treated as their unaccented forms (in Czech, A-Á, E-É-Ě, I-Í, O-Ó, U-Ú-Ů, Y-Ý, and in Slovak, A-Á-Ä, E-É, I-Í, O-Ó-Ô, U-Ú, Y-Ý), but then they are sorted after the unaccented letters (for example, the correct lexicographic order is baa, baá, báa, báá, bab, báb, bac, bác, bač, báč [in Czech] and baa, baá, baä, báa, báá, báä, bäa, bäá, bää, bab, báb, bäb, bac, bác, bäc, bač, báč, bäč [in Slovak]). Accented consonants have primary collating weight and are collated immediately after their unaccented counterparts, with exception of Ď, Ň and Ť (in Czech) and Ď, Ĺ, Ľ, Ň, Ŕ and Ť (in Slovak), which have again secondary weight. [[Ch (digraph)|CH]] is considered to be a separate letter and goes between [[H]] and [[I]]. In Slovak, [[Dz (digraph)|DZ]] and [[DŽ]] are also considered separate letters and are positioned between [[Ď]] and [[E]].
* In the [[Danish and Norwegian alphabet]]s, the same extra vowels as in Swedish (see below) are also present but in a different order and with different [[glyph]]s (..., X, Y, Z, [[Æ]], [[Ø]], [[Å]]). Also, "Aa" collates as an equivalent to "Å". The Danish alphabet has traditionally seen "W" as a variant of "V", but today "W" is considered a separate letter.
* In [[Dutch language|Dutch]] the combination IJ (representing [[IJ (letter)|Ĳ]]) was formerly to be collated as Y (or sometimes as a separate letter: Y < IJ < Z), but is currently mostly collated as 2 letters (II < IJ < IK). Exceptions are phone directories; IJ is always collated as Y here because in many Dutch family names Y is used where modern spelling would require IJ. Note that a word starting with ij that is written with a capital I is also written with a capital J, for example, the town [[IJmuiden]], the river [[IJssel]] and the country IJsland ([[Iceland]]).
* In [[Esperanto]], consonants with [[circumflex]] accents ([[c-circumflex|ĉ]], [[g-circumflex|ĝ]], [[h-circumflex|ĥ]], [[j-circumflex|ĵ]], [[s-circumflex|ŝ]]), as well as [[u-breve|ŭ]] (u with [[breve]]), are counted as separate letters and collated separately (c, ĉ, d, e, f, g, ĝ, h, ĥ, i, j, ĵ ... s, ŝ, t, u, ŭ, v, z).
* In [[Estonian language|Estonian]] [[õ]], [[ä]], [[ö]] and [[ü]] are considered separate letters and collate after [[w]]. Letters [[š]], [[z]] and [[ž]] appear in loanwords and foreign proper names only and follow the letter [[s]] in the [[Estonian alphabet]], which otherwise does not differ from the basic Latin alphabet.
* The [[Faroese alphabet]] also has some of the Danish, Norwegian, and Swedish extra letters, namely [[Æ]] and [[Ø]]. Furthermore, the [[Faroese alphabet]] uses the Icelandic eth, which follows the [[D]]. Five of the six vowels [[A]], [[I]], [[O]], [[U]] and [[Y]] can get accents and are after that considered separate letters. The consonants [[C]], [[Q]], [[X]], [[W]] and [[Z]] are not found. Therefore, the first five letters are [[A]], [[Á]], [[B]], [[D]] and [[Ð]], and the last five are [[V]], [[Y]], [[Ý]], [[Æ]], [[Ø]]
* In [[Filipino language|Filipino]] (Tagalog) and other Philippine languages, the letter Ng is treated as a separate letter. It is pronounced as in ''sing'', ''ping-pong'', etc. By itself, it is pronounced ''nang'', but in general [[Filipino orthography]], it is spelled as if it were two separate letters (n and g). Also, letter derivatives (such as [[Ñ]]) immediately follow the base letter. Filipino also is written with diacritics, but their use is very rare (except the [[tilde]]).
* The [[Finnish alphabet]] and collating rules are the same as those of Swedish.
* For [[French language|French]], the ''last'' accent in a given word determines the order.<ref name=unicode10>{{cite web| title=Unicode Technical Standard #10: Unicode collation algorithm| publisher=Unicode, Inc. (unicode.org)| date=20 March 2008| url=https://unicode.org/reports/tr10/| access-date=27 August 2008| archive-date=27 August 2008| archive-url=https://web.archive.org/web/20080827003801/http://www.unicode.org/reports/tr10/| url-status=live}}</ref> For example, in French, the following four words would be sorted this way: cote < côte < coté < côté. The letter e is ordered as e é è ê ë (œ considered as  oe), same thing for o as ô ö.
* In [[German alphabet|German]] letters with [[Diaeresis (diacritic)|umlaut]] ([[Ä]], [[Ö]], [[Ü]]) are treated generally just like their non-umlauted versions; [[ß]] is always sorted as ss. This makes the alphabetic order Arbeit, Arg, Ärgerlich, Argument, Arm, Assistant, Aßlar, Assoziation. For phone directories and similar lists of names, the umlauts are to be collated like the letter combinations "ae", "oe", "ue" because a number of German surnames appear both with umlaut and in the non-umlauted form with "e" (Müller/Mueller). This makes the alphabetic order Udet, Übelacker, Uell, Ülle, Ueve, Üxküll, Uffenbach.
* The [[Hungarian language|Hungarian]] vowels have accents, umlauts, and double accents, while consonants are written with single, double (digraphs) or triple (trigraph) characters. In collating, accented vowels are equivalent with their non-accented counterparts and double and triple characters follow their single originals. Hungarian alphabetic order is: A=Á, B, C, Cs, D, Dz, Dzs, E=É, F, G, Gy, H, I=Í, J, K, L, Ly, M, N, Ny, O=Ó, Ö=Ő, P, Q, R, S, Sz, T, Ty, U=Ú, Ü=Ű, V, W, X, Y, Z, Zs. (Before 1984, ''dz'' and ''dzs'' were not considered single letters for collation, but two letters each, d+z and d+zs instead.) It means that e.g. ''nádcukor'' should precede ''nádcsomó'' (even though ''s'' normally precedes ''u''), since ''c'' precedes ''cs'' in the collation. Difference in vowel length should only be taken into consideration if the two words are otherwise identical (e.g. ''egér, éger''). Spaces and hyphens within phrases are ignored in collation. ''Ch'' also occurs as a digraph in certain words but it is not considered as a grapheme on its own right in terms of collation.
*:A particular feature of Hungarian collation is that contracted forms of double di- and trigraphs (such as {{lang|hu|ggy}} from ''gy&nbsp;+&nbsp;gy'' or {{lang|hu|ddzs}} from ''dzs&nbsp;+&nbsp;dzs'') should be collated as if they were written in full (independently of the fact of the contraction and the elements of the di- or trigraphs). For example, ''kaszinó'' should precede ''kassza'' (even though the fourth character ''z'' would normally come after ''s'' in the alphabet), because the fourth "character" ([[grapheme]]) of the word ''kassza'' is considered a second ''sz'' (decomposing ''ssz'' into ''sz&nbsp;+&nbsp;sz''), which does follow ''i'' (in ''kaszinó'').<!-- source: 14. c) of the Rules of Hungarian Orthography, cf. [[Hungarian orthography]] -->
* In [[Icelandic language|Icelandic]], [[Þ]] is added, and D is followed by [[Ð]]. Each vowel (A, E, I, O, U, Y) is followed by its correspondent with [[Acute accent|acute]]: Á, É, Í, Ó, Ú, Ý. There is no Z, so the alphabet ends: ... X, Y, Ý, [[Þ]], [[Æ]], Ö.
** Both letters were also used by [[Anglo-Saxons|Anglo-Saxon]] scribes who also used the Runic letter [[Wynn]] to represent /w/.
** [[thorn (letter)|Þ]] (called thorn; lowercase þ) is also a Runic letter.
** [[Eth (letter)|Ð]] (called eth; lowercase ð) is the letter [[D]] with an added stroke.
* [[Kiowa language|Kiowa]] is ordered on phonetic principles, like the [[Brahmic scripts]], rather than on the historical Latin order. Vowels come first, then stop consonants ordered from the front to the back of the mouth, and from negative to positive [[voice-onset time]], then the affricates, fricatives, liquids, and nasals:
:: A, AU, E, I, O, U, B, F, P, V, D, J, T, TH, G, C, K, Q, CH, X, S, Z, L, Y, W, H, M, N
* In [[Lithuanian language|Lithuanian]], specifically Lithuanian letters go after their Latin originals. Another change is that [[Y]] comes just before [[J]]: ... G, H, I, Į, Y, J, K...
* In [[Maltese alphabet]] the digraphs GĦ and IE are treated as single letters, and each is listed after the first character of the pair. The dotted letters (Ċ Ġ Ż) are collated before their originals, while Ħ is after H. Accents, apostrophes and hyphens are ignored. However, when two words sort identically these diacritics are taken into consideration, such that accented letters follow non-accented.
* In [[Polish language|Polish]], specifically Polish letters derived from the Latin alphabet are collated after their originals: A, Ą, B, C, Ć, D, E, Ę, ..., L, Ł, M, N, Ń, O, Ó, P, ..., S, Ś, T, ..., Z, Ź, Ż. The digraphs for collation purposes are treated as if they were two separate letters.
* In [[Pinyin alphabetical order]], where words have the same basic letters in pinyin and differ only in modifying diacritics, the unmodified letter comes before the modified letter. For example, {{angbr|e}} comes before {{angbr|ê}} (額 (''è'') before 欸 (''ê̄'')), and {{angbr|u}} comes before and {{angbr|ü}} (路 (''lù'') before 驢 (''lǘ'') and 努 (''nǔ'') before 女 (''nǚ'')). Characters with the same pinyin letters (including modified letters {{angbr|ê}} and {{angbr|ü}}) are arranged according to their tones in the order of "first tone (i.e., "flat tone"), second tone (rising tone), third tone (falling-rising tone), fourth tone (falling tone), fifth tone (neutral tone)", for example "媽 (''mā''), 麻 (''má''), 馬 (''mǎ''), 罵 (''mà''), 嗎 (''ma'')".{{efn| There is an exception: In [[ABC Chinese–English Dictionary]] the tone order is "zero tone (neutral tone), first tone (flat tone), second tone (rising tone), third tone (falling-rising tone) and fourth tone (falling tone)".}}
* In [[Portuguese alphabet|Portuguese]], the collating order is just like in English: A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, X, Y, Z. Digraphs and letters with diacritics are not included in the alphabet.
* In [[Romanian language|Romanian]], special characters derived from the Latin alphabet are collated after their originals: A, Ă, Â, ..., I, Î, ..., S, Ș, T, Ț, ..., Z.
* In [[Serbo-Croatian]] and other related South Slavic languages, the five accented characters and three conjoined characters are sorted after the originals: ..., C, Č, Ć, D, DŽ, Đ, E, ..., L, LJ, M, N, NJ, O, ..., S, Š, T, ..., Z, Ž.
* [[Spanish alphabet|Spanish]] treated (until 1994) "CH" and "LL" as single letters, giving an ordering of ''{{Wikt-lang|es|cinco}}, {{Wikt-lang|es|credo}}, {{Wikt-lang|es|chispa}}'' and ''{{Wikt-lang|es|lomo}}, {{Wikt-lang|es|luz}}, {{Wikt-lang|es|llama}}.'' This is not true any more since in 1994 the [[Real Academia Española|RAE]] adopted the more conventional usage, and now LL is collated between LK and LM, and CH between CG and CI. The six characters with diacritics Á, É, Í, Ó, Ú, Ü are treated as the original letters A, E, I, O, U, for example: ''{{Wikt-lang|es|radio}}, {{Wikt-lang|es|ráfaga}}, {{Wikt-lang|es|rana}}, {{Wikt-lang|es|rápido}}, {{Wikt-lang|es|rastrillo}}.'' The only Spanish-specific collating question is [[Ñ]] ({{Wikt-lang|es|eñe}}) as a different letter collated after N.
* In the [[Swedish alphabet]], there are three extra [[vowel]]s placed at its end (..., X, Y, Z, [[Å]], [[Ä]], [[Ö]]), similar to the Danish and Norwegian alphabet, but with different glyphs and a different collating order. The letter "W" has been treated as a variant of "V", but in the 13th edition of ''[[Svenska Akademiens Ordlista|Svenska Akademiens ordlista]]'' (2006) "W" was considered a separate letter.
* In the [[Turkish alphabet]] there are six additional letters: ç, ğ, ı, ö, ş, and ü (but no q, w, and x). They are collated with ç after c, ğ after g, ı ''before'' i, ö after o, ş after s, and ü after u. Originally, when the alphabet was introduced in 1928, ı was collated after i, but the order was changed later so that letters having shapes containing dots, cedilles or other adorning marks always follow the letters with corresponding bare shapes. Note that in Turkish orthography the letter I is the majuscule of dotless ı, whereas İ is the majuscule of dotted i.
* In many [[Turkic languages]] (such as [[Azeri language|Azeri]] or the [[Yañalif|Jaꞑalif]] orthography for [[Tatar language|Tatar]]), there used to be the letter [[Gha]] (Ƣƣ), which came between [[G]] and [[H]]. It is now in disuse.
* In [[Vietnamese language|Vietnamese]], there are seven additional letters: [[ă]], [[â]], [[đ]], [[ê]], [[ô]], [[ơ]], [[ư]] while [[f]], [[j]], [[w]], [[z]] are absent, even though they are still in some use (like Internet address, foreign loan language). "f" is replaced by the combination "ph". The same as for "w" is "qu".
* In [[Volapük]] [[ä]], [[ö]] and [[ü]] are counted as separate letters and collated separately (a, ä, b ... o, ö, p ... u, ü, v) while [[q]] and [[w]] are absent.<ref>{{Cite web |last=Midgley |first=Ralph |title=Volapük to English dictionary |url=http://volap%C3%BCk.com/VoEnDictionary-20100830.pdf |archive-url=https://web.archive.org/web/20120901034151/http://xn--volapk-7ya.com/VoEnDictionary-20100830.pdf |archive-date=1 September 2012 |url-status=dead |df=dmy |access-date=24 September 2019 }}</ref>
* In [[Welsh language|Welsh]] the digraphs CH, DD, FF, NG, LL, PH, RH, and TH are treated as single letters, and each is listed after the first character of the pair (except for NG which is listed after G), producing the order A, B, C, CH, D, DD, E, F, FF, G, NG, H, and so on. It can sometimes happen, however, that word compounding results in the juxtaposition of two letters which do ''not'' form a digraph. An example is the word LLONGYFARCH (composed from LLON + GYFARCH). This results in such an ordering as, for example, LAWR, LWCUS, LLONG, LLOM, LLONGYFARCH (NG is a digraph in LLONG, but not in LLONGYFARCH). The letter combination R+H (as distinct from the digraph RH) may similarly arise by juxtaposition in compounds, although this tends not to produce any pairs in which misidentification could affect the ordering. For the other potentially confusing letter combinations that may occur – namely, D+D and L+L – a hyphen is used in the spelling (e.g. AD-DAL, CHWIL-LYS).

==Automation==
{{Further|Collation#Automation}}
[[Collation algorithm]]s (in combination with [[sorting algorithm]]s) are used in computer programming to place strings in alphabetical order. A standard example is the [[Unicode Collation Algorithm]], which can be used to put strings containing any [[Unicode]] symbols into (an extension of) alphabetical order.<ref name=unicode10/> It can be made to conform to most of the language-specific conventions described above by tailoring its default collation table. Several such tailorings are collected in [[Common Locale Data Repository]].

==Similar orderings==
{{Unreferenced section|date=June 2017}}
The principle behind alphabetical ordering can still be applied in languages that do not strictly speaking use an [[alphabet]] – for example, they may be written using a [[syllabary]] or [[abugida]] – provided the symbols used have an established ordering.

For [[logograph]]ic writing systems, such as Chinese [[hanzi]] or Japanese [[kanji]], the method of [[radical-and-stroke sorting]] is frequently used as a way of defining an ordering on the symbols. Japanese sometimes uses pronunciation order, most commonly with the [[Gojūon]] order but sometimes with the older [[Iroha]] ordering.

In mathematics, [[lexicographical order]] is a means of ordering sequences in a manner analogous to that used to produce alphabetical order.<ref name="BaaderNipkow1999">{{cite book|author1=Franz Baader|author2=Tobias Nipkow|title=Term Rewriting and All That|year=1999|publisher=Cambridge University Press|isbn=978-0-521-77920-3|pages=18–19}}</ref>

Some computer applications use a version of alphabetical order that can be achieved using a very simple [[algorithm]], based purely on the [[ASCII]] or [[Unicode]] codes for characters. This may have non-standard effects such as placing all capital letters before lower-case ones. See [[ASCIIbetical order]].

A [[rhyming dictionary]] is based on sorting words in alphabetical order starting from the last to the first letter of the word.

==See also==
*[[Collation]]
*[[Sorting]]
*[[Ugaritic alphabet]], giving the first example of such an ordering 

==Notes==
{{Notelist}}

==References==
{{reflist}}

==Further reading==
* Chauvin, Yvonne. ''Pratique du classement alphabétique''. 4th ed. Paris: Bordas, 1977. {{ISBN|2-04-010155-1}}
*[[Judith Flanders|Flanders, Judith]]. ''A Place for Everything: The Curious History of Alphabetical Order''. New York: Basic Books / Hatchette Books, 2020. {{ISBN|978-1-5416-7507-0}}

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[[Category:Alphabets]]
[[Category:Collation]]