11 Facts About Unicode equivalence

Unicode equivalence is the specification by the Unicode character encoding standard that some sequences of code points represent essentially the same character.

The code point U+006E followed by U+0303 is defined by Unicode to be canonically equivalent to the single code point U+00F1.

For each of the two equivalence notions, Unicode defines two normal forms, one fully composed, and one fully decomposed.

Compatibility or other reasons, Unicode equivalence sometimes assigns two different code points to entities that are essentially the same character.

Consistency with some older standards, Unicode equivalence provides single code points for many characters that could be viewed as modified forms of other characters or as combinations of two or more characters.

Consistency with other standards, and for greater flexibility, Unicode equivalence provides codes for many elements that are not used on their own, but are meant instead to modify or combine with a preceding base character.

Unicode equivalence provides code points for some characters or groups of characters which are modified only for aesthetic reasons, or to add new semantics without losing the original one.

Unicode equivalence provides two normal forms that are semantically meaningful for each of the two compatibility criteria: the composed forms NFC and NFKC, and the decomposed forms NFD and NFKD.

For defective Unicode equivalence strings starting with a Hangul vowel or trailing conjoining jamo, concatenation can break Composition.

Unicode equivalence assigns each character a combining class, which is identified by a numerical value.

In one specific instance, OS X normalized Unicode equivalence filenames sent from the Samba file- and printer-sharing software.