Halfwidth and Fullwidth Forms is the name of a

Unicode block A Unicode block is one of several contiguous ranges of numeric character codes ( code points) of the Unicode character set that are defined by the Unicode Consortium for administrative and documentation purposes. Typically, proposals such as the ...

U+FF00–FFEF, provided so that older encodings containing both halfwidth and fullwidth characters can have lossless translation to/from Unicode. It is the second-to-last block of the

Basic Multilingual Plane In the Unicode standard, a plane is a continuous group of 65,536 (216) code points. There are 17 planes, identified by the numbers 0 to 16, which corresponds with the possible values 00–1016 of the first two positions in six position hexadecima ...

, followed only by the short Specials block at U+FFF0–FFFF. Its block name in Unicode 1.0 was Halfwidth and Fullwidth Variants. Range U+FF01–FF5E reproduces the characters of

ASCII ASCII ( ), abbreviated from American Standard Code for Information Interchange, is a character encoding standard for electronic communication. ASCII codes represent text in computers, telecommunications equipment, and other devices. Because ...

21 to 7E as fullwidth forms. U+FF00 does not correspond to a fullwidth ASCII 20 (space character), since that role is already fulfilled by U+3000 "

ideographic space In computer programming, whitespace is any character or series of characters that represent horizontal or vertical space in typography. When rendered, a whitespace character does not correspond to a visible mark, but typically does occupy an area ...

". Range U+FF61–FF9F encodes halfwidth forms of

katakana is a Japanese syllabary, one component of the Japanese writing system along with hiragana, kanji and in some cases the Latin script (known as rōmaji). The word ''katakana'' means "fragmentary kana", as the katakana characters are derived f ...

and related punctuation in a transposition of A1 to DF in the

JIS X 0201 JIS X 0201, a Japanese Industrial Standard developed in 1969 (then called JIS C 6220 until the JIS category reform), was the first Japanese electronic character set to become widely used. It is either a 7-bit encoding or an 8-bit encoding, altho ...

encoding – see

half-width kana are katakana characters displayed compressed at half their normal width (a 1:2 aspect ratio), instead of the usual square (1:1) aspect ratio. For example, the usual (full-width) form of the katakana ''ka'' is カ while the half-width form is ｶ. ...

. The range U+FFA0–FFDC encodes halfwidth forms of compatibility jamo characters for

Hangul The Korean alphabet, known as Hangul, . Hangul may also be written as following South Korea's standard Romanization. ( ) in South Korea and Chosŏn'gŭl in North Korea, is the modern official writing system for the Korean language. The le ...

, in a transposition of their 1974 standard layout. It is used in the mapping of some IBM encodings for Korean, such as IBM code page 933, which allows the use of the

Shift Out and Shift In characters Shift Out (SO) and Shift In (SI) are ASCII control characters 14 and 15, respectively (0x0E and 0x0F). These are sometimes also called "Control-N" and "Control-O". The original meaning of those characters provided a way to shift a coloured ribbon ...

to shift to a double-byte character set. Since the double-byte character set could contain compatibility jamo, halfwidth variants are needed to provide round-trip compatibility. Range U+FFE0–FFEE includes fullwidth and halfwidth symbols.

Block

The block has variation sequences defined for East Asian punctuation positional variants. They use (VS01) and (VS02): An additional variant is defined for a fullwidth zero with a short diagonal stroke: U+FF10 FULLWIDTH DIGIT ZERO, U+FE00 VS1 (０︀).

History

The following Unicode-related documents record the purpose and process of defining specific characters in the Halfwidth and Fullwidth Forms block:

References

{{Unicode navigation Unicode blocks Latin-script Unicode blocks Kana *Halfwidth

Block

History

See also

References