Editing O (section)

==Related characters==
{{see also|Circle symbol (disambiguation){{!}}circle symbol}}
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===Descendants and related characters in the Latin alphabet===
{{Flowlist|
* Œ œ : Latin [[Œ|''OE'']] ligature
* O with [[diacritic]]s: [[Ø|Ø ø]] [[Ǿ|Ǿ ǿ]] [[Ö|Ö ö]] [[Ȫ|Ȫ ȫ]] [[Ó|Ó ó]] [[Ò|Ò ò]] [[circumflex|Ô ô]] [[Ố|Ố ố]] [[Ồ|Ồ ồ]] [[Ổ|Ổ ổ]] [[Ỗ|Ỗ ỗ]] [[Ộ|Ộ ộ]] [[caron|Ǒ ǒ]] [[double acute accent|Ő ő]] [[breve|Ŏ ŏ]] [[Ȏ|Ȏ ȏ]] [[Dot (diacritic)|Ȯ ȯ]] [[Ȱ|Ȱ ȱ]] [[Dot (diacritic)|Ọ ọ]] [[Ɵ|Ɵ ɵ]] [[ᶱ]]<ref>{{cite web|url=https://www.unicode.org/L2/L2004/04132-n2740-phonetic.pdf|title=L2/04-132 Proposal to add additional phonetic characters to the UCS|date=2004-04-19|first=Peter|last=Constable}}</ref> [[Ơ|Ơ ơ]] [[Ớ|Ớ ớ]] [[Ờ|Ờ ờ]] [[Ỡ|Ỡ ỡ]] [[Ợ|Ợ ợ]] [[Ở|Ở ở]] [[Hook above|Ỏ ỏ]] [[Macron (diacritic)|Ō ō]] [[Ṓ|Ṓ ṓ]] [[Ṑ|Ṑ ṑ]] [[Õ|Õ õ]] [[Ȭ|Ȭ ȭ]] [[Ṍ|Ṍ ṍ]] [[Ṏ|Ṏ ṏ]] [[ogonek|Ǫ ǫ]] [[double grave accent|Ȍ ȍ]] O̩ o̩ Ó̩ ó̩ Ò̩ ò̩ [[Ǭ|Ǭ ǭ]] O͍ o͍
* [[Ꝍ|Ꝍ ꝍ]] : O with loop was used in some [[North Germanic languages|medieval Nordic]] [[Orthography|orthographies]]<ref name="unicode2006">{{cite web|url=https://www.unicode.org/L2/L2006/06027-n3027-medieval.pdf|title=L2/06-027: Proposal to add Medievalist characters to the UCS|date=2006-01-30|first1=Michael|last1=Everson|first2=Peter|last2=Baker|first3=António|last3=Emiliano|first4=Florian|last4=Grammel|first5=Odd Einar|last5=Haugen|first6=Diana|last6=Luft|first7=Susana|last7=Pedro|first8=Gerd|last8=Schumacher|first9=Andreas|last9=Stötzner}}</ref>
* Ꟁ ꟁ : [[Old Polish]] O<ref>{{Cite web|title=L2/21-039: Proposal to include the letter 'Old Polish O'|url=https://www.unicode.org/L2/L2021/21039-old-polish-o.pdf|date=2021-01-12|first=Daniel|last=Bunčić}}</ref>
* ⱺ : Small o with low ring inside is used in the [[Swedish Dialect Alphabet]]<ref>{{cite web|url=https://www.unicode.org/L2/L2006/06036-lma-proposal.pdf|title=L2/06-036: Proposal to encode characters for Ordbok över Finlands svenska folkmål in the UCS|date=2006-01-26|first1=Therese|last1=Lemonen|first2=Klaas|last2=Ruppel|first3=Erkki I.|last3=Kolehmainen|first4=Caroline|last4=Sandström}}</ref>
* [[International Phonetic Alphabet|IPA]]-specific symbols related to O: {{IPA link|ɔ}}
* [[International Phonetic Alphabet#Superscript IPA|IPA superscript letters]]:<ref>{{Cite web|title=L2/20-252R: Unicode request for IPA modifier-letters (a), pulmonic|url=https://www.unicode.org/L2/L2020/20252r-mod-ipa-a.pdf|date=2020-11-08|first1=Kirk|last1=Miller|first2=Michael|last2=Ashby}}</ref> 𐞢 𐞣
* [[Uralic Phonetic Alphabet]]-specific symbols related to O:<ref>{{cite web|url=https://www.unicode.org/L2/L2002/02141-n2419-uralic-phonetic.pdf|title=L2/02-141: Uralic Phonetic Alphabet characters for the UCS|date=2002-03-20|first1=Michael|last1=Everson|author-link1=Michael Everson|display-authors=etal}}</ref>
** {{Unichar|1D0F|LATIN LETTER SMALL CAPITAL O}}
** {{Unichar|1D3C|MODIFIER LETTER CAPITAL O}}
** {{Unichar|1D52|MODIFIER LETTER SMALL O}}
** {{Unichar|1D11|LATIN SMALL LETTER SIDEWAYS O}}
** {{Unichar|1D13|LATIN SMALL LETTER SIDEWAYS O WITH STROKE}}
** {{Unichar|1D16|LATIN SMALL LETTER TOP HALF O}}
** {{Unichar|1D17|LATIN SMALL LETTER BOTTOM HALF O}}
** {{Unichar|1D54|MODIFIER LETTER SMALL TOP HALF O}}
** {{Unichar|1D55|MODIFIER LETTER SMALL BOTTOM HALF O}}
* [[Teuthonista]] phonetic transcription-specific symbols related to O:<ref>{{cite web|url=https://www.unicode.org/L2/L2011/11202-n4081-teuthonista.pdf|title=L2/11-202: Revised proposal to encode "Teuthonista" phonetic characters in the UCS|date=2011-06-02|first1=Michael|last1=Everson|first2=Alois|last2=Dicklberger|first3=Karl|last3=Pentzlin|first4=Eveline|last4=Wandl-Vogt}}</ref>
** {{Unichar|AB3D|LATIN SMALL LETTER BLACKLETTER O}}
** {{Unichar|AB3E|LATIN SMALL LETTER BLACKLETTER O WITH STROKE}}
** {{Unichar|AB3F|LATIN SMALL LETTER OPEN O WITH STROKE}}
** {{Unichar|AB43|LATIN SMALL LETTER TURNED O OPEN-O}}
** {{Unichar|AB44|LATIN SMALL LETTER TURNED O OPEN-O WITH STROKE}}
* <sub>o</sub> : Subscript small o is used in [[Indo-European studies]]<ref>{{cite web|url=https://www.unicode.org/L2/L2004/04191-n2788-laryngeals.pdf|title=L2/04-191: Proposal to encode six Indo-Europeanist phonetic characters in the UCS|date=2004-06-07|first1=Deborah|last1=Anderson|first2=Michael|last2=Everson}}</ref>
* 𝼛 : Latin small letter o with retroflex hook is used in [[phonetic transcription]]<ref name="L220125">{{Cite web|title=L2/20-125R: Unicode request for expected IPA retroflex letters and similar letters with hooks|url=https://www.unicode.org/L2/L2020/20125r-ipa-retroflex.pdf|date=2020-07-11|first=Kirk|last=Miller}}</ref><ref name="L221021">{{Cite web|title=L2/21-021: Reference doc numbers for L2/20-266R "Consolidated code chart of proposed phonetic characters" and IPA etc. code point and name changes|url=https://www.unicode.org/L2/L2021/21021-consolidated-ipa.pdf|date=2020-12-07|first=Deborah|last=Anderson}}</ref>
}}

===Derived signs, symbols and abbreviations===
* Ꝋ ꝋ : Forms of O were used for medieval [[scribal abbreviation]]s<ref name="unicode2006"/>
* ∅ : [[Empty set|empty set symbol]]<ref>{{cite web|url=https://jeff560.tripod.com/set.html|title=Earliest Uses of Symbols of Set Theory and Logic|website=jeff560.tripod.com}}</ref>
* º : Masculine [[ordinal indicator]]
* Calligraphic ''O'' (𝒪, 𝓸): [[Mathematical Alphanumeric Symbols]]<ref>{{Cite web |title=Script (or Calligraphic) |url=https://www.w3.org/TR/xml-entity-names/script.html |access-date=2024-01-03 |website=www.w3.org}}</ref>

===Ancestors and siblings in other alphabets===
* 𐤏 : [[Phoenician alphabet|Semitic]] letter [[Ayin]], from which the following symbols originally derive:
** Ω ω : [[Greek alphabet|Greek]] letter [[Omega]]
** Ο ο : Greek letter [[Omicron]]
*** {{Script|Copt|Ⲟ ⲟ}} : [[Coptic alphabet|Coptic]] letter O, which derives from Greek omicron
*** О о : [[Cyrillic]] letter [[O (Cyrillic)|O]], which also derives from Omicron
*** 𐌏 : [[Old Italic script|Old Italic]] O, which derives from Greek Omicron, and is the ancestor of modern Latin O
*** Օ օ : [[Armenian alphabet|Armenian letter O]]{{citation needed|date=October 2015}}

{{anchor|Codes for computing}}