U+0308 was added to Unicode in version 1.1 (1993). It belongs to the block Combining Diacritical Marks in the Basic Multilingual Plane.

This character is a Nonspacing Mark and inherits its script property from the preceding character. The character is also known as double dot above, umlaut, Greek dialytika and double derivative.

The glyph is not a composition. It has a Ambiguous East Asian Width. In bidirectional context it acts as Nonspacing Mark and is not mirrored. The glyph can, under circumstances, be confused with 7 other glyphs. In text U+0308 behaves as Combining Mark regarding line breaks. It has type Extend for sentence and Extend for word breaks. The Grapheme Cluster Break is Extend.

The Wikipedia has the following information about this codepoint:

The diaeresis (/daɪˈɛrɨsɨs/, dy-ERR-ə-səs; plural: diaereses), also spelled diæresis or dieresis and also known as the trema or the umlaut, is a diacritical mark that consists of two dots ( ¨ ) placed over a letter, usually a vowel. When that letter is an i or a j, the diacritic replaces the tittle: ï.

The diaeresis and the umlaut are diacritics marking two distinct phonological phenomena. The diaeresis represents the phenomenon also known as diaeresis or hiatus in which a vowel letter is not pronounced as part of a digraph or diphthong. The umlaut (/ˈʊmlaʊt/ UUM-lowt), in contrast, indicates a sound shift. These two diacritics originated separately; the diaeresis is considerably older. Nevertheless, in modern computer systems using Unicode, the umlaut and diaeresis diacritics are identical, e.g. U+00E4 ä latin small letter a with diaeresis (HTML ä · ä) represents both a-umlaut and a-diaeresis.

The same symbol is also used as a diacritic in other cases, distinct from both diaeresis and umlaut. For example, in Albanian, ë represents a schwa.


System Representation
UTF-8 CC 88
UTF-16 03 08
UTF-32 00 00 03 08
URL-Quoted %CC%88
HTML-Escape ̈
Wrong windows-1252 Mojibake ̈
alias double dot above
alias umlaut
alias Greek dialytika
alias double derivative
LaTeX \"

Related Characters

  • ¨
  • Ä
  • Ë
  • Ï
  • Ö
  • Ü
  • ä
  • ë
  • ï
  • ö
  • ü
  • ÿ
  • Ÿ
  • ̈́
  • ΅
  • ΐ
  • Ϊ
  • Ϋ
  • ΰ
  • ϊ
  • ϋ
  • ϔ
  • Ё
  • Ї
  • ё
  • ї
  • Ӓ
  • ӓ
  • Ӛ
  • ӛ
  • Ӝ
  • ӝ
  • Ӟ
  • ӟ
  • Ӥ
  • ӥ
  • Ӧ
  • ӧ
  • Ӫ
  • ӫ
  • Ӭ
  • ӭ
  • Ӱ
  • ӱ
  • Ӵ
  • ӵ
  • Ӹ
  • ӹ
  • Ḧ
  • ḧ
  • Ṏ
  • ṏ
  • Ṻ
  • ṻ
  • Ẅ
  • ẅ
  • Ẍ
  • ẍ
  • ẗ
  • ῁
  • ῒ
  • ΐ
  • ῗ
  • ῢ
  • ΰ
  • ῧ
  • ῭
  • ΅


  • ߳
  • ⍡
  • ⍢
  • ⍣
  • ⍤
  • ⍨
  • ⸚


Complete Record

Property Value
Age (age) 1.1
Unicode 1 Name (na1) NON-SPACING DIAERESIS
Block (blk) Diacriticals
General Category (gc) Nonspacing Mark
Script (sc) Inherited
Bidirectional Category (bc) Nonspacing Mark
Combining Class (ccc) Above
Decomposition Type (dt) None
Decomposition Mapping (dm) ̈
Lowercase (Lower)
Simple Lowercase Mapping (slc) ̈
Lowercase Mapping (lc) ̈
Uppercase (Upper)
Simple Uppercase Mapping (suc) ̈
Uppercase Mapping (uc) ̈
Simple Titlecase Mapping (stc) ̈
Titlecase Mapping (tc) ̈
Case Folding (cf) ̈
ASCII Hex Digit (AHex)
Alphabetic (Alpha)
Bidi Control (Bidi_C)
Bidi Mirrored (Bidi_M)
Bidi Paired Bracket (bpb) ̈
Bidi Paired Bracket Type (bpt) None
Cased (Cased)
Composition Exclusion (CE)
Case Ignorable (CI)
Full Composition Exclusion (Comp_Ex)
Changes When Casefolded (CWCF)
Changes When Casemapped (CWCM)
Changes When NFKC Casefolded (CWKCF)
Changes When Lowercased (CWL)
Changes When Titlecased (CWT)
Changes When Uppercased (CWU)
Dash (Dash)
Deprecated (Dep)
Default Ignorable Code Point (DI)
Diacritic (Dia)
East Asian Width (ea) Ambiguous
Extender (Ext)
FC NFKC Closure (FC_NFKC) ̈
Grapheme Cluster Break (GCB) Extend
Grapheme Base (Gr_Base)
Grapheme Extend (Gr_Ext)
Hex Digit (Hex)
Hangul Syllable Type (hst) Not Applicable
Hyphen (Hyphen)
ID Continue (IDC)
Ideographic (Ideo)
ID Start (IDS)
IDS Binary Operator (IDSB)
IDS Trinary Operator and (IDST)
Indic Positional Category (InPC) NA
Indic Syllabic Category (InSC) Other
ISO 10646 Comment (isc)
Joining Group (jg) No_Joining_Group
Join Control (Join_C)
Jamo Short Name (JSN)
Joining Type (jt) Transparent
Line Break (lb) Combining Mark
Logical Order Exception (LOE)
Math (Math)
Noncharacter Code Point (NChar)
NFC Quick Check (NFC_QC) Maybe
NFD Quick Check (NFD_QC) Yes
NFKC Casefold (NFKC_CF) ̈
NFKC Quick Check (NFKC_QC) Maybe
NFKD Quick Check (NFKD_QC) Yes
Numeric Type (nt) None
Numeric Value (nv) NaN
Other Alphabetic (OAlpha)
Other Default Ignorable Code Point (ODI)
Other Grapheme Extend (OGr_Ext)
Other ID Continue (OIDC)
Other ID Start (OIDS)
Other Lowercase (OLower)
Other Math (OMath)
Other Uppercase (OUpper)
Pattern Syntax (Pat_Syn)
Pattern White Space (Pat_WS)
Quotation Mark (QMark)
Radical (Radical)
Sentence Break (SB) Extend
Simple Case Folding (scf) ̈
Script Extension (scx) Inherited
Soft Dotted (SD)
STerm (STerm)
Terminal Punctuation (Term)
Unified Ideograph (UIdeo)
Variation Selector (VS)
Word Break (WB) Extend
White Space (WSpace)
XID Continue (XIDC)
XID Start (XIDS)
Expands On NFC (XO_NFC)
Expands On NFD (XO_NFD)
Expands On NFKC (XO_NFKC)
Expands On NFKD (XO_NFKD)