View source for Specials (Unicode block)


{{More citations needed|date=April 2010}}
{{Infobox Unicode block
|blockname = Specials
|rangestart = FFF0
|rangeend = FFFF
|script1 = [[Script (Unicode)#Special script property values|Common]]
|1_0_0 = 1
|2_1 = 1
|3_0 = 3
|nonchar = 2
|note = <ref>{{cite web|url=https://www.unicode.org|title=Unicode character database|work=The Unicode Standard|access-date=2016-07-09}}</ref><ref>{{cite web|url=https://www.unicode.org/versions/enumeratedversions.html|title=Enumerated Versions of The Unicode Standard|work=The Unicode Standard|access-date=2016-07-09}}</ref>
}}

'''Specials''' is a short [[Unicode]] block of characters put at the very end of the [[Basic Multilingual Plane]], at U+FFF0&ndash;FFFF. Of these 16 code points, five have been used since Unicode 3.0:
*{{unichar|FFF9|INTERLINEAR ANNOTATION ANCHOR}}, marks start of [[Interlinear gloss|annotated text]]
*{{unichar|FFFA|INTERLINEAR ANNOTATION SEPARATOR}}, marks start of annotating character(s)
*{{unichar|FFFB|INTERLINEAR ANNOTATION TERMINATOR}}, marks end of annotation block
*<span id="OBJ">{{unichar|FFFC|OBJECT REPLACEMENT CHARACTER}}</span>, placeholder in the text for another unspecified object, for example in a [[compound document]].
*{{unichar|FFFD|REPLACEMENT CHARACTER}} used to replace an unknown, unrecognized, or unrepresentable character
*{{unichar|FFFE|}} not a character.
*{{unichar|FFFF|}} not a character.

FFFE and FFFF are not unused in the usual way, but [[Universal Character Set characters#Non-characters|guaranteed not to be Unicode characters at all]]. They can be used to guess a text's scheme, since any text using these is not a correctly encoded Unicode text. Unicode's {{unichar|FEFF|[[Byte order mark]]}} character can be put at the start of a Unicode text to signal its [[endianness]]: a program reading such a text and finding 0xFFFE would then know that it should switch the byte order for all the following characters.

Its block name in Unicode 1.0 was '''Special'''.<ref>{{cite web |url=https://www.unicode.org/versions/Unicode1.0.0/CodeCharts2.pdf |work=The Unicode Standard |version=version 1.0 |title=3.8: Block-by-Block Charts |publisher=[[Unicode Consortium]]}}</ref>

==Replacement character==
[[File:Replacement character.svg|thumb|Replacement character]]
The '''replacement character''' (�) (often displayed as a black [[rhombus]] with a white question mark) is a symbol found in the [[Unicode]] standard at code point U+FFFD in the ''Specials'' table. It is used for problems when something is unable to render a stream of data to a correct symbol.<ref name="Wichary fallback">{{cite web |last1=Wichary |first1=Marcin |title=When Fonts Fall |url=https://www.figma.com/blog/when-fonts-fall/ |publisher=Figma |access-date=6 June 2021}}</ref> It is usually seen when the data is not valid and does not match any character:

Consider a text file containing the German word {{lang|de|für}} (meaning 'for') in the [[ISO-8859-1]] encoding (<code>0x66 0xFC 0x72</code>). This file is now opened with a text editor that thinks that the input is [[UTF-8]]. The first and last byte are valid UTF-8 encodings of ASCII, but the middle byte (<code>0xFC</code>) is not a valid byte in UTF-8. So, a text editor could replace this byte with the replacement character symbol to make a valid string of Unicode [[code point]]s. The whole string now looks like this: "f�r".

A poorly made text editor might save the replacement character in UTF-8, and the text file data will then look like this: <code>0x66 0xEF 0xBF 0xBD 0x72</code>, which will be displayed in ISO-8859-1 as "fï¿½r" (this is called [[mojibake]]). Since the replacement is the same for all errors this makes it impossible to get the first character. A better (but harder to make) way is to keep the original bytes, including the error, and only convert to the replacement when ''displaying'' the text. This will allow the text editor to save the original byte sequence, while still showing the error to the user.

At one time the replacement character was used a lot when there was no [[glyph]] that can be used in a font for that character. However, most new text rendering systems instead use a font's {{tt|[[.notdef]]}} character, which most times is an empty box (or "?" or "X" in a box<ref>{{cite web |title=Recommendations for OpenType Fonts (OpenType 1.7) - Typography |url=https://docs.microsoft.com/en-us/typography/opentype/otspec170/recom#shape-of-notdef-glyph |website=docs.microsoft.com |access-date=18 October 2020 |language=en-us}}</ref>), sometimes called a "[[Noto_fonts#Etymology|tofu]]" (this browser displays 􏿾). There is no Unicode point for this symbol.

So, the replacement character is now only seen for encoding errors, such as invalid UTF-8. Some software tries to hide this by [[Translation|translating]] the bytes of invalid UTF-8 to matching characters in [[Windows-1252]] (since that is the most likely source of these errors), so that the replacement character is never seen.

==Unicode chart==
{{Unicode chart Specials}}

==History==
The following Unicode-related documents record the purpose and process of defining specific characters in the Specials block:

{| class="wikitable collapsible"
|-
! [[Unicode#Versions|Version]] !! {{nobr|Final code points<ref group=lower-alpha name=final/>}} !! Count !! [[Unicode Consortium|UTC]]&nbsp;ID !! [[International Committee for Information Technology Standards|L2]]&nbsp;ID !! [[ISO/IEC JTC 1/SC 2|WG2]]&nbsp;ID !! Document
|-
| rowspan="5" | 1.0.0 || U+FFFD || 1 || || || || (to be determined)
|-
| rowspan="4" | U+FFFE..FFFF || rowspan="4" | 2 || || || || (to be determined)
|-
| || {{nobr|[https://www.unicode.org/consortium/utc-minutes/UTC-088-200108.html L2/01-295R]}} || || {{Citation|title=Minutes from the UTC/L2 meeting #88|date=2001-11-06|first=Lisa|last=Moore|section=Motion 88-M2}}
|-
| || {{nobr|[https://www.unicode.org/L2/L2001/01355-FFFF_in_UTF-8.htm L2/01-355]}} || {{nobr|[https://www.unicode.org/wg2/docs/n2369.htm N2369 (html],}} [https://www.unicode.org/wg2/docs/n2369.doc doc]) || {{Citation|title=Request to allow FFFF, FFFE in UTF-8 in the text of ISO/IEC 10646|date=2001-09-26|first=Mark|last=Davis|author-link=Mark Davis (Unicode)}}
|-
| || {{nobr|[https://www.unicode.org/L2/L2002/02154-n2403-minutes.pdf L2/02-154]}} || [https://www.unicode.org/wg2/docs/n2403.pdf N2403] || {{Citation|title=Draft minutes of WG 2 meeting 41, Hotel Phoenix, Singapore, 2001-10-15/19|date=2002-04-22|first=V. S.|last=Umamaheswaran|section=9.3 Allowing FFFF and FFFE in UTF-8}}
|-
| rowspan="8" | 2.1 || rowspan="8" | U+FFFC || rowspan="8" | 1 || {{nobr|UTC/1995-056}} || || || {{Citation|title=Recommendation to encode a WCH_EMBEDDING character|date=1995-12-06|first=Murray|last=Sargent}}
|-
| {{nobr|[https://www.unicode.org/L2/L1996-UTC/UTC67-Minutes.TXT UTC/1996-002]}} || || || {{Citation|title=UTC #67 Minutes|date=1996-03-05|first1=Joan|last1=Aliprand|first2=Edwin|last2=Hart|first3=Steve|last3=Greenfield|section=Embedded Objects}}
|-
| || || N1365 || {{Citation|title=Proposal Summary – Object Replacement Character|date=1996-03-18|first=Murray|last=Sargent}}
|-
| || || [http://std.dkuug.dk/jtc1/sc2/wg2/docs/n1353.doc N1353] {{Webarchive|url=https://web.archive.org/web/20170222235007/http://std.dkuug.dk/jtc1/sc2/wg2/docs/n1353.doc |date=2017-02-22 }} || {{Citation|title=Draft minutes of WG2 Copenhagen Meeting # 30|date=1996-06-25|first1=V. S.|last1=Umamaheswaran|first2=Mike|last2=Ksar|section=8.14}}
|-
| || {{nobr|L2/97-288}} || [http://std.dkuug.dk/jtc1/sc2/wg2/docs/n1603.doc N1603] || {{Citation|title=Unconfirmed Meeting Minutes, WG 2 Meeting # 33, Heraklion, Crete, Greece, 20 June – 4 July 1997|date=1997-10-24|first=V. S.|last=Umamaheswaran|section=7.3}}
|-
| || {{nobr|[https://www.unicode.org/L2/L1998/98004R.pdf L2/98-004R]}} || N1681 || {{Citation|title=Text of ISO 10646 – AMD 18 for PDAM registration and FPDAM ballot|date=1997-12-22}}
|-
| || {{nobr|[https://www.unicode.org/L2/L1998/98070.pdf L2/98-070]}} || || {{Citation|title=Minutes of the joint UTC and L2 meeting from the meeting in Cupertino, February 25-27, 1998|first1=Joan|last1=Aliprand|first2=Arnold|last2=Winkler|section=Additional comments regarding 2.1}}
|-
| || {{nobr|[https://www.unicode.org/L2/L1998/02n3188.pdf L2/98-318]}} || [http://std.dkuug.dk/jtc1/sc2/wg2/docs/n1894_02n3188_fpdam%2018.pdf N1894] || {{Citation|title=Revised text of 10646-1/FPDAM 18, AMENDMENT 18: Symbols and Others|date=1998-10-22}}
|-
| rowspan="18" | 3.0 || rowspan="18" | U+FFF9..FFFB || rowspan="18" | 3 || || {{nobr|[https://www.unicode.org/L2/L1997/97255r.pdf L2/97-255R]}} || || {{Citation|title=Approved Minutes – UTC #73 & L2 #170 joint meeting, Palo Alto, CA – August 4-5, 1997|date=1997-12-03|first=Joan|last=Aliprand|section=3.D Proposal for In-Line Notation (ruby)}}
|-
| || {{nobr|[https://www.unicode.org/L2/L1998/98055.pdf L2/98-055]}} || || {{Citation|title=Support for Implementing Inline and Interlinear Annotations|date=1998-02-22|first=Asmus|last=Freytag}}
|-
| || {{nobr|[https://www.unicode.org/L2/L1998/98070.pdf L2/98-070]}} || || {{Citation|title=Minutes of the joint UTC and L2 meeting from the meeting in Cupertino, February 25-27, 1998|first1=Joan|last1=Aliprand|first2=Arnold|last2=Winkler|section=3.C.5. Support for implementing inline and interlinear annotations}}
|-
| || {{nobr|L2/98-099}} || N1727 || {{Citation|title=Support for Implementing Interlinear Annotations as used in East Asian Typography|date=1998-03-18|first=Asmus|last=Freytag}}
|-
| || {{nobr|[https://www.unicode.org/L2/L1998/98158.html L2/98-158]}} || || {{Citation|title=Draft Minutes – UTC #76 & NCITS Subgroup L2 #173 joint meeting, Tredyffrin, Pennsylvania, April 20-22, 1998|date=1998-05-26|first1=Joan|last1=Aliprand|first2=Arnold|last2=Winkler|section=Inline and Interlinear Annotations}}
|-
| || {{nobr|L2/98-286}} || [http://std.dkuug.dk/jtc1/sc2/wg2/docs/n1703w97.doc N1703] {{Webarchive|url=https://web.archive.org/web/20201003015217/http://std.dkuug.dk/jtc1/sc2/wg2/docs/n1703w97.doc |date=2020-10-03 }} || {{Citation|title=Unconfirmed Meeting Minutes, WG 2 Meeting #34, Redmond, WA, USA; 1998-03-16--20|date=1998-07-02|first1=V. S.|last1=Umamaheswaran|first2=Mike|last2=Ksar|section=8.14}}
|-
| || {{nobr|L2/98-270}} || || {{Citation|title=Suggestion to the inline and interlinear annotation proposal|date=1998-07-29|first1=Hideki|last1=Hiura|first2=Tatsuo|last2=Kobayashi|author-link2=Tatsuo Kobayashi}}
|-
| || {{nobr|[https://www.unicode.org/L2/L1998/98281r.pdf L2/98-281R (pdf],}} [https://www.unicode.org/L2/L1998/98281R.htm html]) || || {{Citation|title=Unconfirmed Minutes – UTC #77 & NCITS Subgroup L2 # 174 JOINT MEETING, Redmond, WA -- July 29-31, 1998|date=1998-07-31|first=Joan|last=Aliprand|section=In-Line and Interlinear Annotation (III.C.1.c)}}
|-
| || {{nobr|L2/98-363}} || [https://www.unicode.org/wg2/docs/n1861.pdf N1861] || {{Citation|title=Ruby markers|date=1998-09-01|first=T. K.|last=Sato}}
|-
| || {{nobr|L2/98-372}} || {{nobr|[https://www.unicode.org/wg2/docs/n1884.pdf N1884R2 (pdf],}} [https://www.unicode.org/wg2/docs/n1884.doc doc]) || {{Citation|title=Additional Characters for the UCS|date=1998-09-22|first1=Ken|last1=Whistler|display-authors=etal}}
|-
| || {{nobr|L2/98-416}} || {{nobr|[https://www.unicode.org/wg2/docs/n1882.zip N1882.zip]}} || {{Citation|title=Support for Implementing Interlinear Annotations|date=1998-09-23}}
|-
| || {{nobr|[https://www.unicode.org/L2/L1998/02n3210.pdf L2/98-329]}} || [http://std.dkuug.dk/jtc1/sc2/wg2/docs/n1920_02n3210_text_pdam_30_addlatin.pdf N1920] {{Webarchive|url=https://web.archive.org/web/20201002233957/http://std.dkuug.dk/jtc1/sc2/wg2/docs/n1920_02n3210_text_pdam_30_addlatin.pdf |date=2020-10-02 }} || {{Citation|title=Combined PDAM registration and consideration ballot on WD for ISO/IEC 10646-1/Amd. 30, AMENDMENT 30: Additional Latin and other characters|date=1998-10-28}}
|-
| || {{nobr|[https://www.unicode.org/L2/L1998/98421.htm L2/98-421R]}} || || {{Citation|title=Notes concerning the PDAM 30 interlinear annotation characters|date=1998-12-04|first1=Michel|last1=Suignard|first2=Hideki|last2=Hiura}}
|-
| || {{nobr|[https://www.unicode.org/L2/L1999/n1903.rtf L2/99-010]}} || {{nobr|[https://www.unicode.org/wg2/docs/n1903.pdf N1903 (pdf],}} [https://www.unicode.org/wg2/docs/n1903.htm html], [https://www.unicode.org/wg2/docs/n1903w97.doc doc]) || {{Citation|title=Minutes of WG 2 meeting 35, London, U.K.; 1998-09-21--25|date=1998-12-30|first=V. S.|last=Umamaheswaran|section=8.2.15}}
|-
| || {{nobr|[https://www.unicode.org/L2/L1998/98419.pdf L2/98-419 (pdf],}} [https://www.unicode.org/L2/L1998/98419.doc doc]) || || {{Citation|title=Approved Minutes -- UTC #78 & NCITS Subgroup L2 # 175 Joint Meeting, San Jose, CA -- December 1-4, 1998|date=1999-02-05|first=Joan|last=Aliprand|section=Interlinear Annotation Characters}}
|-
| {{nobr|[https://www.unicode.org/L2/L1999-UTC/u1999-021.txt UTC/1999-021]}} || || || {{Citation|title=W3C XML CG statement on annotation characters|date=1999-06-08|first1=Martin|last1=Duerst|first2=Jon|last2=Bosak|author-link2=Jon Bosak}}
|-
| || {{nobr|[https://www.unicode.org/L2/L1999/99176.htm L2/99-176R]}} || || {{Citation|title=Minutes from the joint UTC/L2 meeting in Seattle, June 8-10, 1999|date=1999-11-04|first=Lisa|last=Moore|section=W3C Liaison Statement on Annotation Characters}}
|-
| || {{nobr|[https://www.unicode.org/L2/L2001/01301-deprecation.txt L2/01-301]}} || || {{Citation|title=Analysis of Character Deprecation in the Unicode Standard|date=2001-08-01|first=Ken|last=Whistler|section=E. Indicated as "strongly discouraged" for plain text interchange}}
|- class="sortbottom"
| colspan="7" | {{reflist|group=lower-alpha|refs=<ref name=final>Proposed code points and characters names may differ from final code points and names</ref>}}
|}

==Related pages==
* [[Unicode control characters]]

== References ==
{{Reflist}}

{{Unicode navigation}}

[[Category:Unicode blocks|Specials]]