ICU:NFD 和 NFC 是什么意思?

ICU: What does NFD and NFC mean?

我找到了一个片段,上面写着

Any-Latin; NFD; [:Nonspacing Mark:] Remove; NFC; [:Punctuation:] Remove; Lower();

...并且应该使任意字符串很好地适合 URL。

所以,我猜分号之间的东西类似于"commands",它们将被执行,但是NDF和NFC具体代表什么?我真的在官方文档中什么也没找到...

有关完整示例,请参阅 ICU transliterators and the linked page on TR15 normalization forms

Normalization Form D (NFD) Canonical Decomposition

Normalization Form C (NFC) Canonical Decomposition, followed by Canonical Composition

Normalization Form KD (NFKD) Compatibility Decomposition

Normalization Form KC (NFKC) Compatibility Decomposition, followed by Canonical Composition