为什么大写字母不足以进行不区分大小写的比较？
Why is upper casing not enough for case-insensitive comparison?
要不区分大小写地比较两个字符串，一种正确的方法是区分大小写
先折叠它们。这比上壳或下壳好在哪里？
我找到了小写字母无法在线正常工作的例子。为了
例如“σ”和“ς”（“Σ”的两种形式）在以下情况下不会变得相同
转换为小写。但我没找到为什么折叠是
比映射到大写更好。有没有两个字符串的情况
应该不区分大小写地匹配，不要大写相同
字符串？
另一种情况是我想存储不区分大小写的索引。这
推荐的方式似乎是折叠大小写然后归一化。什么是
它比存储映射到大写的字符串的优点和
归一化？规范说不能保证映射到大写
跨版本的 Unicode 稳定，而大小写折叠是。但是有没有
映射到大写字母的任何情况都会在
早期版本的 Unicode？
根据 Unicode stability policy，大小写映射仅对大小写对稳定，即字符对 X 和 Y 其中X是Y的完整大写映射，Y是[=22的完整小写映射=]X。只有当这两个字符都具有这些属性时，它们之间的大小写关系才是固定的。
但是，Unicode 包含许多“不完整”的大小写对，其中仅对小写形式进行了编码，而大写形式则完全缺失。对于传统上仅使用小写字母的转录系统中使用的字母，通常就是这种情况。如果大写形式被发现并随后添加到 Unicode，这些字母将收到一个新的大写映射。
发生这种情况的最新字符是“ʂ”（来自 Unicode 1.1）、“ᶎ”（来自 Unicode 4.1）和“ꞔ”（来自 Unicode 7.0），它们都有全新的大写形式（ Ꞔ, Ʂ, Ᶎ) 两年前的 Unicode 12.0.
因为大小写映射不必是唯一的，这使得大写不能很好地替代正确的大小写折叠。例如，U+0434 (д) 和 U+1C81 (ᲁ) 都大写到 U+0414 (Д)，但只有前者由于是 U+0414 的完整小写映射而被锁定在大小写对中。如果有人在某个旧手稿中找到U+1C81的专用大写字母版本，就会给它一个新的大写映射，导致U+0434和U+1C81在那个操作下突然不再比较相等。
编辑： 我刚刚想起一个大写字母不足以进行不区分大小写匹配的当前示例：U+1E9E (ẞ) 已经是大写字母，因此大写字母本身。它的小写对应是 U+00DF (ß)，但 U+00DF 的大写映射是序列 (SS).
uppercase("ẞ") ≠ uppercase(lowercase("ẞ"))
我从 here 中找到了一个列表。
从 Unicode 13.0.0 开始。
具有超过 1 个大写映射的等价物 类。
case fold
original
UPPER CASE
k 006B LATIN SMALL LETTER K
K 004B LATIN CAPITAL LETTER K
K 004B LATIN CAPITAL LETTER K
k 006B LATIN SMALL LETTER K
K 004B LATIN CAPITAL LETTER K
K 212A KELVIN SIGN
K 212A KELVIN SIGN
ss 0073 LATIN SMALL LETTER S; 0073 LATIN SMALL LETTER S
ß 00DF LATIN SMALL LETTER SHARP S
SS 0053 LATIN CAPITAL LETTER S; 0053 LATIN CAPITAL LETTER S
ẞ 1E9E LATIN CAPITAL LETTER SHARP S
ẞ 1E9E LATIN CAPITAL LETTER SHARP S
å 00E5 LATIN SMALL LETTER A WITH RING ABOVE
Å 00C5 LATIN CAPITAL LETTER A WITH RING ABOVE
Å 00C5 LATIN CAPITAL LETTER A WITH RING ABOVE
å 00E5 LATIN SMALL LETTER A WITH RING ABOVE
Å 00C5 LATIN CAPITAL LETTER A WITH RING ABOVE
Å 212B ANGSTROM SIGN
Å 212B ANGSTROM SIGN
θ 03B8 GREEK SMALL LETTER THETA
Θ 0398 GREEK CAPITAL LETTER THETA
Θ 0398 GREEK CAPITAL LETTER THETA
θ 03B8 GREEK SMALL LETTER THETA
Θ 0398 GREEK CAPITAL LETTER THETA
ϑ 03D1 GREEK THETA SYMBOL
Θ 0398 GREEK CAPITAL LETTER THETA
ϴ 03F4 GREEK CAPITAL THETA SYMBOL
ϴ 03F4 GREEK CAPITAL THETA SYMBOL
ω 03C9 GREEK SMALL LETTER OMEGA
Ω 03A9 GREEK CAPITAL LETTER OMEGA
Ω 03A9 GREEK CAPITAL LETTER OMEGA
ω 03C9 GREEK SMALL LETTER OMEGA
Ω 03A9 GREEK CAPITAL LETTER OMEGA
Ω 2126 OHM SIGN
Ω 2126 OHM SIGN
并用于小写。
case fold
original
lower case
s 0073 LATIN SMALL LETTER S
S 0053 LATIN CAPITAL LETTER S
s 0073 LATIN SMALL LETTER S
s 0073 LATIN SMALL LETTER S
s 0073 LATIN SMALL LETTER S
ſ 017F LATIN SMALL LETTER LONG S
ſ 017F LATIN SMALL LETTER LONG S
st 0073 LATIN SMALL LETTER S; 0074 LATIN SMALL LETTER T
ſt FB05 LATIN SMALL LIGATURE LONG S T
ſt FB05 LATIN SMALL LIGATURE LONG S T
st FB06 LATIN SMALL LIGATURE ST
st FB06 LATIN SMALL LIGATURE ST
β 03B2 GREEK SMALL LETTER BETA
Β 0392 GREEK CAPITAL LETTER BETA
β 03B2 GREEK SMALL LETTER BETA
β 03B2 GREEK SMALL LETTER BETA
β 03B2 GREEK SMALL LETTER BETA
ϐ 03D0 GREEK BETA SYMBOL
ϐ 03D0 GREEK BETA SYMBOL
ε 03B5 GREEK SMALL LETTER EPSILON
Ε 0395 GREEK CAPITAL LETTER EPSILON
ε 03B5 GREEK SMALL LETTER EPSILON
ε 03B5 GREEK SMALL LETTER EPSILON
ε 03B5 GREEK SMALL LETTER EPSILON
ϵ 03F5 GREEK LUNATE EPSILON SYMBOL
ϵ 03F5 GREEK LUNATE EPSILON SYMBOL
θ 03B8 GREEK SMALL LETTER THETA
Θ 0398 GREEK CAPITAL LETTER THETA
θ 03B8 GREEK SMALL LETTER THETA
θ 03B8 GREEK SMALL LETTER THETA
θ 03B8 GREEK SMALL LETTER THETA
ϑ 03D1 GREEK THETA SYMBOL
ϑ 03D1 GREEK THETA SYMBOL
ϴ 03F4 GREEK CAPITAL THETA SYMBOL
θ 03B8 GREEK SMALL LETTER THETA
ι 03B9 GREEK SMALL LETTER IOTA
◌ͅ 0345 COMBINING GREEK YPOGEGRAMMENI
◌ͅ 0345 COMBINING GREEK YPOGEGRAMMENI
Ι 0399 GREEK CAPITAL LETTER IOTA
ι 03B9 GREEK SMALL LETTER IOTA
ι 03B9 GREEK SMALL LETTER IOTA
ι 03B9 GREEK SMALL LETTER IOTA
ι 1FBE GREEK PROSGEGRAMMENI
ι 1FBE GREEK PROSGEGRAMMENI
ΐ 03B9 GREEK SMALL LETTER IOTA; 0308 COMBINING DIAERESIS; 0301 COMBINING ACUTE ACCENT
ΐ 0390 GREEK SMALL LETTER IOTA WITH DIALYTIKA AND TONOS
ΐ 0390 GREEK SMALL LETTER IOTA WITH DIALYTIKA AND TONOS
ΐ 1FD3 GREEK SMALL LETTER IOTA WITH DIALYTIKA AND OXIA
ΐ 1FD3 GREEK SMALL LETTER IOTA WITH DIALYTIKA AND OXIA
κ 03BA GREEK SMALL LETTER KAPPA
Κ 039A GREEK CAPITAL LETTER KAPPA
κ 03BA GREEK SMALL LETTER KAPPA
κ 03BA GREEK SMALL LETTER KAPPA
κ 03BA GREEK SMALL LETTER KAPPA
ϰ 03F0 GREEK KAPPA SYMBOL
ϰ 03F0 GREEK KAPPA SYMBOL
μ 03BC GREEK SMALL LETTER MU
µ 00B5 MICRO SIGN
µ 00B5 MICRO SIGN
Μ 039C GREEK CAPITAL LETTER MU
μ 03BC GREEK SMALL LETTER MU
μ 03BC GREEK SMALL LETTER MU
μ 03BC GREEK SMALL LETTER MU
π 03C0 GREEK SMALL LETTER PI
Π 03A0 GREEK CAPITAL LETTER PI
π 03C0 GREEK SMALL LETTER PI
π 03C0 GREEK SMALL LETTER PI
π 03C0 GREEK SMALL LETTER PI
ϖ 03D6 GREEK PI SYMBOL
ϖ 03D6 GREEK PI SYMBOL
ρ 03C1 GREEK SMALL LETTER RHO
Ρ 03A1 GREEK CAPITAL LETTER RHO
ρ 03C1 GREEK SMALL LETTER RHO
ρ 03C1 GREEK SMALL LETTER RHO
ρ 03C1 GREEK SMALL LETTER RHO
ϱ 03F1 GREEK RHO SYMBOL
ϱ 03F1 GREEK RHO SYMBOL
σ 03C3 GREEK SMALL LETTER SIGMA
Σ 03A3 GREEK CAPITAL LETTER SIGMA
σ 03C3 GREEK SMALL LETTER SIGMA
ς 03C2 GREEK SMALL LETTER FINAL SIGMA
ς 03C2 GREEK SMALL LETTER FINAL SIGMA
σ 03C3 GREEK SMALL LETTER SIGMA
σ 03C3 GREEK SMALL LETTER SIGMA
ΰ 03C5 GREEK SMALL LETTER UPSILON; 0308 COMBINING DIAERESIS; 0301 COMBINING ACUTE ACCENT
ΰ 03B0 GREEK SMALL LETTER UPSILON WITH DIALYTIKA AND TONOS
ΰ 03B0 GREEK SMALL LETTER UPSILON WITH DIALYTIKA AND TONOS
ΰ 1FE3 GREEK SMALL LETTER UPSILON WITH DIALYTIKA AND OXIA
ΰ 1FE3 GREEK SMALL LETTER UPSILON WITH DIALYTIKA AND OXIA
φ 03C6 GREEK SMALL LETTER PHI
Φ 03A6 GREEK CAPITAL LETTER PHI
φ 03C6 GREEK SMALL LETTER PHI
φ 03C6 GREEK SMALL LETTER PHI
φ 03C6 GREEK SMALL LETTER PHI
ϕ 03D5 GREEK PHI SYMBOL
ϕ 03D5 GREEK PHI SYMBOL
в 0432 CYRILLIC SMALL LETTER VE
В 0412 CYRILLIC CAPITAL LETTER VE
в 0432 CYRILLIC SMALL LETTER VE
в 0432 CYRILLIC SMALL LETTER VE
в 0432 CYRILLIC SMALL LETTER VE
ᲀ 1C80 CYRILLIC SMALL LETTER ROUNDED VE
ᲀ 1C80 CYRILLIC SMALL LETTER ROUNDED VE
д 0434 CYRILLIC SMALL LETTER DE
Д 0414 CYRILLIC CAPITAL LETTER DE
д 0434 CYRILLIC SMALL LETTER DE
д 0434 CYRILLIC SMALL LETTER DE
д 0434 CYRILLIC SMALL LETTER DE
ᲁ 1C81 CYRILLIC SMALL LETTER LONG-LEGGED DE
ᲁ 1C81 CYRILLIC SMALL LETTER LONG-LEGGED DE
о 043E CYRILLIC SMALL LETTER O
О 041E CYRILLIC CAPITAL LETTER O
о 043E CYRILLIC SMALL LETTER O
о 043E CYRILLIC SMALL LETTER O
о 043E CYRILLIC SMALL LETTER O
ᲂ 1C82 CYRILLIC SMALL LETTER NARROW O
ᲂ 1C82 CYRILLIC SMALL LETTER NARROW O
с 0441 CYRILLIC SMALL LETTER ES
С 0421 CYRILLIC CAPITAL LETTER ES
с 0441 CYRILLIC SMALL LETTER ES
с 0441 CYRILLIC SMALL LETTER ES
с 0441 CYRILLIC SMALL LETTER ES
ᲃ 1C83 CYRILLIC SMALL LETTER WIDE ES
ᲃ 1C83 CYRILLIC SMALL LETTER WIDE ES
т 0442 CYRILLIC SMALL LETTER TE
Т 0422 CYRILLIC CAPITAL LETTER TE
т 0442 CYRILLIC SMALL LETTER TE
т 0442 CYRILLIC SMALL LETTER TE
т 0442 CYRILLIC SMALL LETTER TE
ᲄ 1C84 CYRILLIC SMALL LETTER TALL TE
ᲄ 1C84 CYRILLIC SMALL LETTER TALL TE
ᲅ 1C85 CYRILLIC SMALL LETTER THREE-LEGGED TE
ᲅ 1C85 CYRILLIC SMALL LETTER THREE-LEGGED TE
ъ 044A CYRILLIC SMALL LETTER HARD SIGN
Ъ 042A CYRILLIC CAPITAL LETTER HARD SIGN
ъ 044A CYRILLIC SMALL LETTER HARD SIGN
ъ 044A CYRILLIC SMALL LETTER HARD SIGN
ъ 044A CYRILLIC SMALL LETTER HARD SIGN
ᲆ 1C86 CYRILLIC SMALL LETTER TALL HARD SIGN
ᲆ 1C86 CYRILLIC SMALL LETTER TALL HARD SIGN
ѣ 0463 CYRILLIC SMALL LETTER YAT
Ѣ 0462 CYRILLIC CAPITAL LETTER YAT
ѣ 0463 CYRILLIC SMALL LETTER YAT
ѣ 0463 CYRILLIC SMALL LETTER YAT
ѣ 0463 CYRILLIC SMALL LETTER YAT
ᲇ 1C87 CYRILLIC SMALL LETTER TALL YAT
ᲇ 1C87 CYRILLIC SMALL LETTER TALL YAT
ṡ 1E61 LATIN SMALL LETTER S WITH DOT ABOVE
Ṡ 1E60 LATIN CAPITAL LETTER S WITH DOT ABOVE
ṡ 1E61 LATIN SMALL LETTER S WITH DOT ABOVE
ṡ 1E61 LATIN SMALL LETTER S WITH DOT ABOVE
ṡ 1E61 LATIN SMALL LETTER S WITH DOT ABOVE
ẛ 1E9B LATIN SMALL LETTER LONG S WITH DOT ABOVE
ẛ 1E9B LATIN SMALL LETTER LONG S WITH DOT ABOVE
ꙋ A64B CYRILLIC SMALL LETTER MONOGRAPH UK
ᲈ 1C88 CYRILLIC SMALL LETTER UNBLENDED UK
ᲈ 1C88 CYRILLIC SMALL LETTER UNBLENDED UK
Ꙋ A64A CYRILLIC CAPITAL LETTER MONOGRAPH UK
ꙋ A64B CYRILLIC SMALL LETTER MONOGRAPH UK
ꙋ A64B CYRILLIC SMALL LETTER MONOGRAPH UK
ꙋ A64B CYRILLIC SMALL LETTER MONOGRAPH UK
小写（大写（X））。
case fold
original
lower case of upper case
ss 0073 LATIN SMALL LETTER S; 0073 LATIN SMALL LETTER S
ß 00DF LATIN SMALL LETTER SHARP S
ss 0073 LATIN SMALL LETTER S; 0073 LATIN SMALL LETTER S
ẞ 1E9E LATIN CAPITAL LETTER SHARP S
ß 00DF LATIN SMALL LETTER SHARP S
对于大写(小写)，没有等价组有多个结果。
要不区分大小写地比较两个字符串，一种正确的方法是区分大小写 先折叠它们。这比上壳或下壳好在哪里？
我找到了小写字母无法在线正常工作的例子。为了 例如“σ”和“ς”（“Σ”的两种形式）在以下情况下不会变得相同 转换为小写。但我没找到为什么折叠是 比映射到大写更好。有没有两个字符串的情况 应该不区分大小写地匹配，不要大写相同 字符串？
另一种情况是我想存储不区分大小写的索引。这 推荐的方式似乎是折叠大小写然后归一化。什么是 它比存储映射到大写的字符串的优点和 归一化？规范说不能保证映射到大写 跨版本的 Unicode 稳定，而大小写折叠是。但是有没有 映射到大写字母的任何情况都会在 早期版本的 Unicode？
根据 Unicode stability policy，大小写映射仅对大小写对稳定，即字符对 X 和 Y 其中X是Y的完整大写映射，Y是[=22的完整小写映射=]X。只有当这两个字符都具有这些属性时，它们之间的大小写关系才是固定的。
但是，Unicode 包含许多“不完整”的大小写对，其中仅对小写形式进行了编码，而大写形式则完全缺失。对于传统上仅使用小写字母的转录系统中使用的字母，通常就是这种情况。如果大写形式被发现并随后添加到 Unicode，这些字母将收到一个新的大写映射。
发生这种情况的最新字符是“ʂ”（来自 Unicode 1.1）、“ᶎ”（来自 Unicode 4.1）和“ꞔ”（来自 Unicode 7.0），它们都有全新的大写形式（ Ꞔ, Ʂ, Ᶎ) 两年前的 Unicode 12.0.
因为大小写映射不必是唯一的，这使得大写不能很好地替代正确的大小写折叠。例如，U+0434 (д) 和 U+1C81 (ᲁ) 都大写到 U+0414 (Д)，但只有前者由于是 U+0414 的完整小写映射而被锁定在大小写对中。如果有人在某个旧手稿中找到U+1C81的专用大写字母版本，就会给它一个新的大写映射，导致U+0434和U+1C81在那个操作下突然不再比较相等。
编辑： 我刚刚想起一个大写字母不足以进行不区分大小写匹配的当前示例：U+1E9E (ẞ) 已经是大写字母，因此大写字母本身。它的小写对应是 U+00DF (ß)，但 U+00DF 的大写映射是序列
uppercase("ẞ") ≠ uppercase(lowercase("ẞ"))
我从 here 中找到了一个列表。
从 Unicode 13.0.0 开始。
具有超过 1 个大写映射的等价物 类。
| case fold | original | UPPER CASE |
|---|---|---|
| k 006B LATIN SMALL LETTER K | K 004B LATIN CAPITAL LETTER K | K 004B LATIN CAPITAL LETTER K |
| k 006B LATIN SMALL LETTER K | K 004B LATIN CAPITAL LETTER K | |
| K 212A KELVIN SIGN | K 212A KELVIN SIGN | |
| ss 0073 LATIN SMALL LETTER S; 0073 LATIN SMALL LETTER S | ß 00DF LATIN SMALL LETTER SHARP S | SS 0053 LATIN CAPITAL LETTER S; 0053 LATIN CAPITAL LETTER S |
| ẞ 1E9E LATIN CAPITAL LETTER SHARP S | ẞ 1E9E LATIN CAPITAL LETTER SHARP S | |
| å 00E5 LATIN SMALL LETTER A WITH RING ABOVE | Å 00C5 LATIN CAPITAL LETTER A WITH RING ABOVE | Å 00C5 LATIN CAPITAL LETTER A WITH RING ABOVE |
| å 00E5 LATIN SMALL LETTER A WITH RING ABOVE | Å 00C5 LATIN CAPITAL LETTER A WITH RING ABOVE | |
| Å 212B ANGSTROM SIGN | Å 212B ANGSTROM SIGN | |
| θ 03B8 GREEK SMALL LETTER THETA | Θ 0398 GREEK CAPITAL LETTER THETA | Θ 0398 GREEK CAPITAL LETTER THETA |
| θ 03B8 GREEK SMALL LETTER THETA | Θ 0398 GREEK CAPITAL LETTER THETA | |
| ϑ 03D1 GREEK THETA SYMBOL | Θ 0398 GREEK CAPITAL LETTER THETA | |
| ϴ 03F4 GREEK CAPITAL THETA SYMBOL | ϴ 03F4 GREEK CAPITAL THETA SYMBOL | |
| ω 03C9 GREEK SMALL LETTER OMEGA | Ω 03A9 GREEK CAPITAL LETTER OMEGA | Ω 03A9 GREEK CAPITAL LETTER OMEGA |
| ω 03C9 GREEK SMALL LETTER OMEGA | Ω 03A9 GREEK CAPITAL LETTER OMEGA | |
| Ω 2126 OHM SIGN | Ω 2126 OHM SIGN |
并用于小写。
| case fold | original | lower case |
|---|---|---|
| s 0073 LATIN SMALL LETTER S | S 0053 LATIN CAPITAL LETTER S | s 0073 LATIN SMALL LETTER S |
| s 0073 LATIN SMALL LETTER S | s 0073 LATIN SMALL LETTER S | |
| ſ 017F LATIN SMALL LETTER LONG S | ſ 017F LATIN SMALL LETTER LONG S | |
| st 0073 LATIN SMALL LETTER S; 0074 LATIN SMALL LETTER T | ſt FB05 LATIN SMALL LIGATURE LONG S T | ſt FB05 LATIN SMALL LIGATURE LONG S T |
| st FB06 LATIN SMALL LIGATURE ST | st FB06 LATIN SMALL LIGATURE ST | |
| β 03B2 GREEK SMALL LETTER BETA | Β 0392 GREEK CAPITAL LETTER BETA | β 03B2 GREEK SMALL LETTER BETA |
| β 03B2 GREEK SMALL LETTER BETA | β 03B2 GREEK SMALL LETTER BETA | |
| ϐ 03D0 GREEK BETA SYMBOL | ϐ 03D0 GREEK BETA SYMBOL | |
| ε 03B5 GREEK SMALL LETTER EPSILON | Ε 0395 GREEK CAPITAL LETTER EPSILON | ε 03B5 GREEK SMALL LETTER EPSILON |
| ε 03B5 GREEK SMALL LETTER EPSILON | ε 03B5 GREEK SMALL LETTER EPSILON | |
| ϵ 03F5 GREEK LUNATE EPSILON SYMBOL | ϵ 03F5 GREEK LUNATE EPSILON SYMBOL | |
| θ 03B8 GREEK SMALL LETTER THETA | Θ 0398 GREEK CAPITAL LETTER THETA | θ 03B8 GREEK SMALL LETTER THETA |
| θ 03B8 GREEK SMALL LETTER THETA | θ 03B8 GREEK SMALL LETTER THETA | |
| ϑ 03D1 GREEK THETA SYMBOL | ϑ 03D1 GREEK THETA SYMBOL | |
| ϴ 03F4 GREEK CAPITAL THETA SYMBOL | θ 03B8 GREEK SMALL LETTER THETA | |
| ι 03B9 GREEK SMALL LETTER IOTA | ◌ͅ 0345 COMBINING GREEK YPOGEGRAMMENI | ◌ͅ 0345 COMBINING GREEK YPOGEGRAMMENI |
| Ι 0399 GREEK CAPITAL LETTER IOTA | ι 03B9 GREEK SMALL LETTER IOTA | |
| ι 03B9 GREEK SMALL LETTER IOTA | ι 03B9 GREEK SMALL LETTER IOTA | |
| ι 1FBE GREEK PROSGEGRAMMENI | ι 1FBE GREEK PROSGEGRAMMENI | |
| ΐ 03B9 GREEK SMALL LETTER IOTA; 0308 COMBINING DIAERESIS; 0301 COMBINING ACUTE ACCENT | ΐ 0390 GREEK SMALL LETTER IOTA WITH DIALYTIKA AND TONOS | ΐ 0390 GREEK SMALL LETTER IOTA WITH DIALYTIKA AND TONOS |
| ΐ 1FD3 GREEK SMALL LETTER IOTA WITH DIALYTIKA AND OXIA | ΐ 1FD3 GREEK SMALL LETTER IOTA WITH DIALYTIKA AND OXIA | |
| κ 03BA GREEK SMALL LETTER KAPPA | Κ 039A GREEK CAPITAL LETTER KAPPA | κ 03BA GREEK SMALL LETTER KAPPA |
| κ 03BA GREEK SMALL LETTER KAPPA | κ 03BA GREEK SMALL LETTER KAPPA | |
| ϰ 03F0 GREEK KAPPA SYMBOL | ϰ 03F0 GREEK KAPPA SYMBOL | |
| μ 03BC GREEK SMALL LETTER MU | µ 00B5 MICRO SIGN | µ 00B5 MICRO SIGN |
| Μ 039C GREEK CAPITAL LETTER MU | μ 03BC GREEK SMALL LETTER MU | |
| μ 03BC GREEK SMALL LETTER MU | μ 03BC GREEK SMALL LETTER MU | |
| π 03C0 GREEK SMALL LETTER PI | Π 03A0 GREEK CAPITAL LETTER PI | π 03C0 GREEK SMALL LETTER PI |
| π 03C0 GREEK SMALL LETTER PI | π 03C0 GREEK SMALL LETTER PI | |
| ϖ 03D6 GREEK PI SYMBOL | ϖ 03D6 GREEK PI SYMBOL | |
| ρ 03C1 GREEK SMALL LETTER RHO | Ρ 03A1 GREEK CAPITAL LETTER RHO | ρ 03C1 GREEK SMALL LETTER RHO |
| ρ 03C1 GREEK SMALL LETTER RHO | ρ 03C1 GREEK SMALL LETTER RHO | |
| ϱ 03F1 GREEK RHO SYMBOL | ϱ 03F1 GREEK RHO SYMBOL | |
| σ 03C3 GREEK SMALL LETTER SIGMA | Σ 03A3 GREEK CAPITAL LETTER SIGMA | σ 03C3 GREEK SMALL LETTER SIGMA |
| ς 03C2 GREEK SMALL LETTER FINAL SIGMA | ς 03C2 GREEK SMALL LETTER FINAL SIGMA | |
| σ 03C3 GREEK SMALL LETTER SIGMA | σ 03C3 GREEK SMALL LETTER SIGMA | |
| ΰ 03C5 GREEK SMALL LETTER UPSILON; 0308 COMBINING DIAERESIS; 0301 COMBINING ACUTE ACCENT | ΰ 03B0 GREEK SMALL LETTER UPSILON WITH DIALYTIKA AND TONOS | ΰ 03B0 GREEK SMALL LETTER UPSILON WITH DIALYTIKA AND TONOS |
| ΰ 1FE3 GREEK SMALL LETTER UPSILON WITH DIALYTIKA AND OXIA | ΰ 1FE3 GREEK SMALL LETTER UPSILON WITH DIALYTIKA AND OXIA | |
| φ 03C6 GREEK SMALL LETTER PHI | Φ 03A6 GREEK CAPITAL LETTER PHI | φ 03C6 GREEK SMALL LETTER PHI |
| φ 03C6 GREEK SMALL LETTER PHI | φ 03C6 GREEK SMALL LETTER PHI | |
| ϕ 03D5 GREEK PHI SYMBOL | ϕ 03D5 GREEK PHI SYMBOL | |
| в 0432 CYRILLIC SMALL LETTER VE | В 0412 CYRILLIC CAPITAL LETTER VE | в 0432 CYRILLIC SMALL LETTER VE |
| в 0432 CYRILLIC SMALL LETTER VE | в 0432 CYRILLIC SMALL LETTER VE | |
| ᲀ 1C80 CYRILLIC SMALL LETTER ROUNDED VE | ᲀ 1C80 CYRILLIC SMALL LETTER ROUNDED VE | |
| д 0434 CYRILLIC SMALL LETTER DE | Д 0414 CYRILLIC CAPITAL LETTER DE | д 0434 CYRILLIC SMALL LETTER DE |
| д 0434 CYRILLIC SMALL LETTER DE | д 0434 CYRILLIC SMALL LETTER DE | |
| ᲁ 1C81 CYRILLIC SMALL LETTER LONG-LEGGED DE | ᲁ 1C81 CYRILLIC SMALL LETTER LONG-LEGGED DE | |
| о 043E CYRILLIC SMALL LETTER O | О 041E CYRILLIC CAPITAL LETTER O | о 043E CYRILLIC SMALL LETTER O |
| о 043E CYRILLIC SMALL LETTER O | о 043E CYRILLIC SMALL LETTER O | |
| ᲂ 1C82 CYRILLIC SMALL LETTER NARROW O | ᲂ 1C82 CYRILLIC SMALL LETTER NARROW O | |
| с 0441 CYRILLIC SMALL LETTER ES | С 0421 CYRILLIC CAPITAL LETTER ES | с 0441 CYRILLIC SMALL LETTER ES |
| с 0441 CYRILLIC SMALL LETTER ES | с 0441 CYRILLIC SMALL LETTER ES | |
| ᲃ 1C83 CYRILLIC SMALL LETTER WIDE ES | ᲃ 1C83 CYRILLIC SMALL LETTER WIDE ES | |
| т 0442 CYRILLIC SMALL LETTER TE | Т 0422 CYRILLIC CAPITAL LETTER TE | т 0442 CYRILLIC SMALL LETTER TE |
| т 0442 CYRILLIC SMALL LETTER TE | т 0442 CYRILLIC SMALL LETTER TE | |
| ᲄ 1C84 CYRILLIC SMALL LETTER TALL TE | ᲄ 1C84 CYRILLIC SMALL LETTER TALL TE | |
| ᲅ 1C85 CYRILLIC SMALL LETTER THREE-LEGGED TE | ᲅ 1C85 CYRILLIC SMALL LETTER THREE-LEGGED TE | |
| ъ 044A CYRILLIC SMALL LETTER HARD SIGN | Ъ 042A CYRILLIC CAPITAL LETTER HARD SIGN | ъ 044A CYRILLIC SMALL LETTER HARD SIGN |
| ъ 044A CYRILLIC SMALL LETTER HARD SIGN | ъ 044A CYRILLIC SMALL LETTER HARD SIGN | |
| ᲆ 1C86 CYRILLIC SMALL LETTER TALL HARD SIGN | ᲆ 1C86 CYRILLIC SMALL LETTER TALL HARD SIGN | |
| ѣ 0463 CYRILLIC SMALL LETTER YAT | Ѣ 0462 CYRILLIC CAPITAL LETTER YAT | ѣ 0463 CYRILLIC SMALL LETTER YAT |
| ѣ 0463 CYRILLIC SMALL LETTER YAT | ѣ 0463 CYRILLIC SMALL LETTER YAT | |
| ᲇ 1C87 CYRILLIC SMALL LETTER TALL YAT | ᲇ 1C87 CYRILLIC SMALL LETTER TALL YAT | |
| ṡ 1E61 LATIN SMALL LETTER S WITH DOT ABOVE | Ṡ 1E60 LATIN CAPITAL LETTER S WITH DOT ABOVE | ṡ 1E61 LATIN SMALL LETTER S WITH DOT ABOVE |
| ṡ 1E61 LATIN SMALL LETTER S WITH DOT ABOVE | ṡ 1E61 LATIN SMALL LETTER S WITH DOT ABOVE | |
| ẛ 1E9B LATIN SMALL LETTER LONG S WITH DOT ABOVE | ẛ 1E9B LATIN SMALL LETTER LONG S WITH DOT ABOVE | |
| ꙋ A64B CYRILLIC SMALL LETTER MONOGRAPH UK | ᲈ 1C88 CYRILLIC SMALL LETTER UNBLENDED UK | ᲈ 1C88 CYRILLIC SMALL LETTER UNBLENDED UK |
| Ꙋ A64A CYRILLIC CAPITAL LETTER MONOGRAPH UK | ꙋ A64B CYRILLIC SMALL LETTER MONOGRAPH UK | |
| ꙋ A64B CYRILLIC SMALL LETTER MONOGRAPH UK | ꙋ A64B CYRILLIC SMALL LETTER MONOGRAPH UK |
小写（大写（X））。
| case fold | original | lower case of upper case |
|---|---|---|
| ss 0073 LATIN SMALL LETTER S; 0073 LATIN SMALL LETTER S | ß 00DF LATIN SMALL LETTER SHARP S | ss 0073 LATIN SMALL LETTER S; 0073 LATIN SMALL LETTER S |
| ẞ 1E9E LATIN CAPITAL LETTER SHARP S | ß 00DF LATIN SMALL LETTER SHARP S |
对于大写(小写)，没有等价组有多个结果。