Special Casing

For most Unicode characters that are affected by casing operations, converting to a different case simply involves replacing a singular code point with another singular code point. Such case mappings – called simple case mappings – can be found in the data file UnicodeData.txt alongside various other properties. However, some case mappings are more complicated than that, mapping one code point to a multi‐character sequence or requiring additional context. These are listed here.

Not all commonly needed case tailorings are defined as part of the core Unicode Standard. Nowadays, the Common Locale Data Repository is the preferred mechanism for such definitions.

See The Unicode Standard, section 3.13: Default Case Algorithms for more information.

Source: SpecialCasing.txt

Unconditional Mappings

Special case mappings without conditions essentially work the same as simple case mappings, but aren’t limited to one‐to‐one relationships. They apply independently of context and language. Note that contrary to their names, the Greek “capital” letters with prosgegrammeni are actually titlecase letters.

Character Lowercase Titlecase Uppercase
German Es‐Zed
00DF ß Latin Small Letter Sharp S 00DF ß 0053 0073 Ss 0053 0053 SS
I with Dot
0130 İ Latin Capital Letter I with Dot Above 0069 0307 i̇ 0130 İ 0130 İ
Ligatures
FB00 ff Latin Small Ligature FF FB00 ff 0046 0066 Ff 0046 0046 FF
FB01 fi Latin Small Ligature FI FB01 fi 0046 0069 Fi 0046 0049 FI
FB02 fl Latin Small Ligature FL FB02 fl 0046 006C Fl 0046 004C FL
FB03 ffi Latin Small Ligature FFI FB03 ffi 0046 0066 0069 Ffi 0046 0046 0049 FFI
FB04 ffl Latin Small Ligature FFL FB04 ffl 0046 0066 006C Ffl 0046 0046 004C FFL
FB05 ſt Latin Small Ligature Long S T FB05 ſt 0053 0074 St 0053 0054 ST
FB06 st Latin Small Ligature ST FB06 st 0053 0074 St 0053 0054 ST
0587 և Armenian Small Ligature Ech Yiwn 0587 և 0535 0582 Եւ 0535 0552 ԵՒ
FB13 ﬓ Armenian Small Ligature Men Now FB13 ﬓ 0544 0576 Մն 0544 0546 ՄՆ
FB14 ﬔ Armenian Small Ligature Men Ech FB14 ﬔ 0544 0565 Մե 0544 0535 ՄԵ
FB15 ﬕ Armenian Small Ligature Men Ini FB15 ﬕ 0544 056B Մի 0544 053B ՄԻ
FB16 ﬖ Armenian Small Ligature Vew Now FB16 ﬖ 054E 0576 Վն 054E 0546 ՎՆ
FB17 ﬗ Armenian Small Ligature Men Xeh FB17 ﬗ 0544 056D Մխ 0544 053D ՄԽ
No Corresponding Uppercase Precomposed Character
0149 ʼn Latin Small Letter N Preceded by Apostrophe 0149 ʼn 02BC 004E ʼN 02BC 004E ʼN
0390 ΐ Greek Small Letter Iota with Dialytika and Tonos 0390 ΐ 0399 0308 0301 Ϊ́ 0399 0308 0301 Ϊ́
03B0 ΰ Greek Small Letter Upsilon with Dialytika and Tonos 03B0 ΰ 03A5 0308 0301 Ϋ́ 03A5 0308 0301 Ϋ́
01F0 ǰ Latin Small Letter J with Caron 01F0 ǰ 004A 030C J̌ 004A 030C J̌
1E96 ẖ Latin Small Letter H with Line Below 1E96 ẖ 0048 0331 H̱ 0048 0331 H̱
1E97 ẗ Latin Small Letter T with Diaeresis 1E97 ẗ 0054 0308 T̈ 0054 0308 T̈
1E98 ẘ Latin Small Letter W with Ring Above 1E98 ẘ 0057 030A W̊ 0057 030A W̊
1E99 ẙ Latin Small Letter Y with Ring Above 1E99 ẙ 0059 030A Y̊ 0059 030A Y̊
1E9A ẚ Latin Small Letter A with Right Half Ring 1E9A ẚ 0041 02BE Aʾ 0041 02BE Aʾ
1F50 ὐ Greek Small Letter Upsilon with Psili 1F50 ὐ 03A5 0313 Υ̓ 03A5 0313 Υ̓
1F52 ὒ Greek Small Letter Upsilon with Psili and Varia 1F52 ὒ 03A5 0313 0300 Υ̓̀ 03A5 0313 0300 Υ̓̀
1F54 ὔ Greek Small Letter Upsilon with Psili and Oxia 1F54 ὔ 03A5 0313 0301 Υ̓́ 03A5 0313 0301 Υ̓́
1F56 ὖ Greek Small Letter Upsilon with Psili and Perispomeni 1F56 ὖ 03A5 0313 0342 Υ̓͂ 03A5 0313 0342 Υ̓͂
1FB6 ᾶ Greek Small Letter Alpha with Perispomeni 1FB6 ᾶ 0391 0342 Α͂ 0391 0342 Α͂
1FC6 ῆ Greek Small Letter Eta with Perispomeni 1FC6 ῆ 0397 0342 Η͂ 0397 0342 Η͂
1FD2 ῒ Greek Small Letter Iota with Dialytika and Varia 1FD2 ῒ 0399 0308 0300 Ϊ̀ 0399 0308 0300 Ϊ̀
1FD3 ΐ Greek Small Letter Iota with Dialytika and Oxia 1FD3 ΐ 0399 0308 0301 Ϊ́ 0399 0308 0301 Ϊ́
1FD6 ῖ Greek Small Letter Iota with Perispomeni 1FD6 ῖ 0399 0342 Ι͂ 0399 0342 Ι͂
1FD7 ῗ Greek Small Letter Iota with Dialytika and Perispomeni 1FD7 ῗ 0399 0308 0342 Ϊ͂ 0399 0308 0342 Ϊ͂
1FE2 ῢ Greek Small Letter Upsilon with Dialytika and Varia 1FE2 ῢ 03A5 0308 0300 Ϋ̀ 03A5 0308 0300 Ϋ̀
1FE3 ΰ Greek Small Letter Upsilon with Dialytika and Oxia 1FE3 ΰ 03A5 0308 0301 Ϋ́ 03A5 0308 0301 Ϋ́
1FE4 ῤ Greek Small Letter Rho with Psili 1FE4 ῤ 03A1 0313 Ρ̓ 03A1 0313 Ρ̓
1FE6 ῦ Greek Small Letter Upsilon with Perispomeni 1FE6 ῦ 03A5 0342 Υ͂ 03A5 0342 Υ͂
1FE7 ῧ Greek Small Letter Upsilon with Dialytika and Perispomeni 1FE7 ῧ 03A5 0308 0342 Ϋ͂ 03A5 0308 0342 Ϋ͂
1FF6 ῶ Greek Small Letter Omega with Perispomeni 1FF6 ῶ 03A9 0342 Ω͂ 03A9 0342 Ω͂
Letters with Ypogegrammeni or Prosgegrammeni
1F80 ᾀ Greek Small Letter Alpha with Psili and Ypogegrammeni 1F80 ᾀ 1F88 ᾈ 1F08 0399 ἈΙ
1F81 ᾁ Greek Small Letter Alpha with Dasia and Ypogegrammeni 1F81 ᾁ 1F89 ᾉ 1F09 0399 ἉΙ
1F82 ᾂ Greek Small Letter Alpha with Psili and Varia and Ypogegrammeni 1F82 ᾂ 1F8A ᾊ 1F0A 0399 ἊΙ
1F83 ᾃ Greek Small Letter Alpha with Dasia and Varia and Ypogegrammeni 1F83 ᾃ 1F8B ᾋ 1F0B 0399 ἋΙ
1F84 ᾄ Greek Small Letter Alpha with Psili and Oxia and Ypogegrammeni 1F84 ᾄ 1F8C ᾌ 1F0C 0399 ἌΙ
1F85 ᾅ Greek Small Letter Alpha with Dasia and Oxia and Ypogegrammeni 1F85 ᾅ 1F8D ᾍ 1F0D 0399 ἍΙ
1F86 ᾆ Greek Small Letter Alpha with Psili and Perispomeni and Ypogegrammeni 1F86 ᾆ 1F8E ᾎ 1F0E 0399 ἎΙ
1F87 ᾇ Greek Small Letter Alpha with Dasia and Perispomeni and Ypogegrammeni 1F87 ᾇ 1F8F ᾏ 1F0F 0399 ἏΙ
1F88 ᾈ Greek Capital Letter Alpha with Psili and Prosgegrammeni 1F80 ᾀ 1F88 ᾈ 1F08 0399 ἈΙ
1F89 ᾉ Greek Capital Letter Alpha with Dasia and Prosgegrammeni 1F81 ᾁ 1F89 ᾉ 1F09 0399 ἉΙ
1F8A ᾊ Greek Capital Letter Alpha with Psili and Varia and Prosgegrammeni 1F82 ᾂ 1F8A ᾊ 1F0A 0399 ἊΙ
1F8B ᾋ Greek Capital Letter Alpha with Dasia and Varia and Prosgegrammeni 1F83 ᾃ 1F8B ᾋ 1F0B 0399 ἋΙ
1F8C ᾌ Greek Capital Letter Alpha with Psili and Oxia and Prosgegrammeni 1F84 ᾄ 1F8C ᾌ 1F0C 0399 ἌΙ
1F8D ᾍ Greek Capital Letter Alpha with Dasia and Oxia and Prosgegrammeni 1F85 ᾅ 1F8D ᾍ 1F0D 0399 ἍΙ
1F8E ᾎ Greek Capital Letter Alpha with Psili and Perispomeni and Prosgegrammeni 1F86 ᾆ 1F8E ᾎ 1F0E 0399 ἎΙ
1F8F ᾏ Greek Capital Letter Alpha with Dasia and Perispomeni and Prosgegrammeni 1F87 ᾇ 1F8F ᾏ 1F0F 0399 ἏΙ
1F90 ᾐ Greek Small Letter Eta with Psili and Ypogegrammeni 1F90 ᾐ 1F98 ᾘ 1F28 0399 ἨΙ
1F91 ᾑ Greek Small Letter Eta with Dasia and Ypogegrammeni 1F91 ᾑ 1F99 ᾙ 1F29 0399 ἩΙ
1F92 ᾒ Greek Small Letter Eta with Psili and Varia and Ypogegrammeni 1F92 ᾒ 1F9A ᾚ 1F2A 0399 ἪΙ
1F93 ᾓ Greek Small Letter Eta with Dasia and Varia and Ypogegrammeni 1F93 ᾓ 1F9B ᾛ 1F2B 0399 ἫΙ
1F94 ᾔ Greek Small Letter Eta with Psili and Oxia and Ypogegrammeni 1F94 ᾔ 1F9C ᾜ 1F2C 0399 ἬΙ
1F95 ᾕ Greek Small Letter Eta with Dasia and Oxia and Ypogegrammeni 1F95 ᾕ 1F9D ᾝ 1F2D 0399 ἭΙ
1F96 ᾖ Greek Small Letter Eta with Psili and Perispomeni and Ypogegrammeni 1F96 ᾖ 1F9E ᾞ 1F2E 0399 ἮΙ
1F97 ᾗ Greek Small Letter Eta with Dasia and Perispomeni and Ypogegrammeni 1F97 ᾗ 1F9F ᾟ 1F2F 0399 ἯΙ
1F98 ᾘ Greek Capital Letter Eta with Psili and Prosgegrammeni 1F90 ᾐ 1F98 ᾘ 1F28 0399 ἨΙ
1F99 ᾙ Greek Capital Letter Eta with Dasia and Prosgegrammeni 1F91 ᾑ 1F99 ᾙ 1F29 0399 ἩΙ
1F9A ᾚ Greek Capital Letter Eta with Psili and Varia and Prosgegrammeni 1F92 ᾒ 1F9A ᾚ 1F2A 0399 ἪΙ
1F9B ᾛ Greek Capital Letter Eta with Dasia and Varia and Prosgegrammeni 1F93 ᾓ 1F9B ᾛ 1F2B 0399 ἫΙ
1F9C ᾜ Greek Capital Letter Eta with Psili and Oxia and Prosgegrammeni 1F94 ᾔ 1F9C ᾜ 1F2C 0399 ἬΙ
1F9D ᾝ Greek Capital Letter Eta with Dasia and Oxia and Prosgegrammeni 1F95 ᾕ 1F9D ᾝ 1F2D 0399 ἭΙ
1F9E ᾞ Greek Capital Letter Eta with Psili and Perispomeni and Prosgegrammeni 1F96 ᾖ 1F9E ᾞ 1F2E 0399 ἮΙ
1F9F ᾟ Greek Capital Letter Eta with Dasia and Perispomeni and Prosgegrammeni 1F97 ᾗ 1F9F ᾟ 1F2F 0399 ἯΙ
1FA0 ᾠ Greek Small Letter Omega with Psili and Ypogegrammeni 1FA0 ᾠ 1FA8 ᾨ 1F68 0399 ὨΙ
1FA1 ᾡ Greek Small Letter Omega with Dasia and Ypogegrammeni 1FA1 ᾡ 1FA9 ᾩ 1F69 0399 ὩΙ
1FA2 ᾢ Greek Small Letter Omega with Psili and Varia and Ypogegrammeni 1FA2 ᾢ 1FAA ᾪ 1F6A 0399 ὪΙ
1FA3 ᾣ Greek Small Letter Omega with Dasia and Varia and Ypogegrammeni 1FA3 ᾣ 1FAB ᾫ 1F6B 0399 ὫΙ
1FA4 ᾤ Greek Small Letter Omega with Psili and Oxia and Ypogegrammeni 1FA4 ᾤ 1FAC ᾬ 1F6C 0399 ὬΙ
1FA5 ᾥ Greek Small Letter Omega with Dasia and Oxia and Ypogegrammeni 1FA5 ᾥ 1FAD ᾭ 1F6D 0399 ὭΙ
1FA6 ᾦ Greek Small Letter Omega with Psili and Perispomeni and Ypogegrammeni 1FA6 ᾦ 1FAE ᾮ 1F6E 0399 ὮΙ
1FA7 ᾧ Greek Small Letter Omega with Dasia and Perispomeni and Ypogegrammeni 1FA7 ᾧ 1FAF ᾯ 1F6F 0399 ὯΙ
1FA8 ᾨ Greek Capital Letter Omega with Psili and Prosgegrammeni 1FA0 ᾠ 1FA8 ᾨ 1F68 0399 ὨΙ
1FA9 ᾩ Greek Capital Letter Omega with Dasia and Prosgegrammeni 1FA1 ᾡ 1FA9 ᾩ 1F69 0399 ὩΙ
1FAA ᾪ Greek Capital Letter Omega with Psili and Varia and Prosgegrammeni 1FA2 ᾢ 1FAA ᾪ 1F6A 0399 ὪΙ
1FAB ᾫ Greek Capital Letter Omega with Dasia and Varia and Prosgegrammeni 1FA3 ᾣ 1FAB ᾫ 1F6B 0399 ὫΙ
1FAC ᾬ Greek Capital Letter Omega with Psili and Oxia and Prosgegrammeni 1FA4 ᾤ 1FAC ᾬ 1F6C 0399 ὬΙ
1FAD ᾭ Greek Capital Letter Omega with Dasia and Oxia and Prosgegrammeni 1FA5 ᾥ 1FAD ᾭ 1F6D 0399 ὭΙ
1FAE ᾮ Greek Capital Letter Omega with Psili and Perispomeni and Prosgegrammeni 1FA6 ᾦ 1FAE ᾮ 1F6E 0399 ὮΙ
1FAF ᾯ Greek Capital Letter Omega with Dasia and Perispomeni and Prosgegrammeni 1FA7 ᾧ 1FAF ᾯ 1F6F 0399 ὯΙ
1FB3 ᾳ Greek Small Letter Alpha with Ypogegrammeni 1FB3 ᾳ 1FBC ᾼ 0391 0399 ΑΙ
1FBC ᾼ Greek Capital Letter Alpha with Prosgegrammeni 1FB3 ᾳ 1FBC ᾼ 0391 0399 ΑΙ
1FC3 ῃ Greek Small Letter Etwa with Ypogegrammeni 1FC3 ῃ 1FCC ῌ 0397 0399 ΗΙ
1FCC ῌ Greek Capital Letter Eta with Prosgegrammeni 1FC3 ῃ 1FCC ῌ 0397 0399 ΗΙ
1FF3 ῳ Greek Small Letter Omega with Ypogegrammeni 1FF3 ῳ 1FFC ῼ 03A9 0399 ΩΙ
1FFC ῼ Greek Capital Letter Omega with Prosgegrammeni 1FF3 ῳ 1FFC ῼ 03A9 0399 ΩΙ
Characters with Ypogegrammeni and No Corresponding Titlecases
1FB2 ᾲ Greek Small Letter Alpha with Varia and Ypogegrammeni 1FB2 ᾲ 1FBA 0345 Ὰͅ 1FBA 0399 ᾺΙ
1FB4 ᾴ Greek Small Letter Alpha with Oxia and Ypogegrammeni 1FB4 ᾴ 0386 0345 Άͅ 0386 0399 ΆΙ
1FC2 ῂ Greek Small Letter Eta with Varia and Ypogegrammeni 1FC2 ῂ 1FCA 0345 Ὴͅ 1FCA 0399 ῊΙ
1FC4 ῄ Greek Small Letter Eta with Oxia and Ypogegrammeni 1FC4 ῄ 0389 0345 Ήͅ 0389 0399 ΉΙ
1FF2 ῲ Greek Small Letter Omega with Varia and Ypogegrammeni 1FF2 ῲ 1FFA 0345 Ὼͅ 1FFA 0399 ῺΙ
1FF4 ῴ Greek Small Letter Omega with Oxia and Ypogegrammeni 1FF4 ῴ 038F 0345 Ώͅ 038F 0399 ΏΙ
1FB7 ᾷ Greek Small Letter Alpha with Perispomeni and Ypogegrammeni 1FB7 ᾷ 0391 0342 0345 ᾼ͂ 0391 0342 0399 Α͂Ι
1FC7 ῇ Greek Small Letter Eta with Perispomeni and Ypogegrammeni 1FC7 ῇ 0397 0342 0345 ῌ͂ 0397 0342 0399 Η͂Ι
1FF7 ῷ Greek Small Letter Omega with Perispomeni and Ypogegrammeni 1FF7 ῷ 03A9 0342 0345 ῼ͂ 03A9 0342 0399 Ω͂Ι
Character Lowercase Titlecase Uppercase

Conditional Mappings

Conditional case mappings require additional context such as the properties of surrounding characters, or even out‐of‐band data like language information. If multiple conditions are listed for a particular mapping, all of them need to be fulfilled for the mapping to apply. If the condition fails, the case algorithm falls back on unconditional and simple mappings. For example, if a non‐final U+03A3 Σ Greek Capital Letter Sigma is lowercased (where finality is defined by the conditions below), it simply becomes U+03C3 σ Greek Small Letter Sigma instead of U+03C2 ς Greek Small Letter Final Sigma.

Character Lowercase Titlecase Uppercase Conditions
Language‐Insensitive Mappings
03A3 Σ Greek Capital Letter Sigma 03C2 ς 03A3 Σ 03A3 Σ
  • Character is preceded by a character with Cased and then zero or more characters with Case_Ignorable
  • Character is not followed by zero or more characters with Case_Ignorable and then a character with Cased
Lithuanian
0307 ̇ Combining Dot Above 0307 ̇ [empty string] [empty string]
  • Language: Lithuanian (lt)
  • Character is preceded by a character with Soft_Dotted, ignoring all intervening characters with CCC ∉ {0, 230}
0049 I Latin Capital Letter I 0069 0307 i̇ 0049 I 0049 I
  • Language: Lithuanian (lt)
  • Character is followed by a character with CCC = 230, ignoring all intervening characters with CCC ∉ {0, 230}
004A J Latin Capital Letter J 006A 0307 j̇ 004A J 004A J
012E Į Latin Capital Letter I with Ogonek 012F 0307 į̇ 012E Į 012E Į
00CC Ì Latin Capital Letter I with Grave 0069 0307 0300 i̇̀ 00CC Ì 00CC Ì
  • Language: Lithuanian (lt)
00CD Í Latin Capital Letter I with Acute 0069 0307 0301 i̇́ 00CD Í 00CD Í
0128 Ĩ Latin Capital Letter I with Tilde 0069 0307 0303 i̇̃ 0128 Ĩ 0128 Ĩ
Turkish and Azerbaijani
0130 İ Latin Capital Letter I with Dot Above 0069 i 0130 İ 0130 İ
  • Language: Turkish (tr) or Azerbaijani (az)
0307 ̇ Combining Dot Above [empty string] 0307 ̇ 0307 ̇
  • Language: Turkish (tr) or Azerbaijani (az)
  • Character is preceded by U+0049, ignoring all intervening characters with CCC ∉ {0, 230}
0049 I Latin Capital Letter I 0131 ı 0049 I 0049 I
  • Language: Turkish (tr) or Azerbaijani (az)
  • Character is not followed by U+0307, ignoring all intervening characters with CCC ∉ {0, 230}
0069 i Latin Small Letter I 0069 i 0130 İ 0130 İ
  • Language: Turkish (tr) or Azerbaijani (az)
Character Lowercase Titlecase Uppercase Conditions