["Unicode"] Re: Why doesn't Ideographic (ID) in UAX#14 have half-width katakana?

suzuki toshiya mpsuzuki at hiroshima-u.ac.jp
Tue Apr 28 03:04:12 CDT 2015

Dear Philippe,

Philippe Verdy wrote:
> My feeeling is that half-width kanas behave like Latin letters and do not
> even have to follow the ideographic composition square to line up with them
> (unlike standard kanas). So effectively their line breaking behavior is
> very different.

Excuse me, do you mean that a half-width kana text should
have the spaces between the words, although full-width
(standard) kana text may not have? Could you tell me more
about the community preferring such distinction?

I think, the orthography proposed to write Japanese language
in Kana without Kanji has the word-breaking space, like,
but it is not officialized, and, it does not distinguish
full-width kana and half-width kana.


> Those "half-width letters" are in fact similar to linear jamos (not
> composed into syllabic squares) in the Korean script, and to Bopomofo
> letters. And may be we could add the CJK key letters (radicals used for
> example in IDS) to this list, or Yi radicals.
> They are harmonized to be used along with other alphabetic scripts. In fact
> they may even not be really "half-width" but proportional. They are also
> used with non-ideographic punctuation (notably the ASCII punctuation) and
> standard SPACE (U+0020).
> If rendered in vertical lines, they could be either rotated (just like
> Latin letters), or not (aligned horizontallly like letters in columns of
> crosswords, but they may also have proportional height, like in
> Latin/Greek/Cyrillic where it is sometimes needed for example with capital
> letters with stacked accents, or when using sized spaces)
> So IMHO, those "half-width" letters are in fact to be considered as another
> separate script, for typographic purpose. They are "unified" with
> non-halfwidth letters, only for collation with minor differences
> (plain-text searching and sorting).
> 2015-04-28 4:20 GMT+02:00 Makoto Kato <m_kato at ga2.so-net.ne.jp>:
>> Hi.
>> http://www.unicode.org/reports/tr14/proposed.html#ID defines Ideographic
>> (ID).  Although full-width katakana is included in ID, half-width
>> katakana (U+FF66 and U+FF71-U+FF9D) isn't.  Why?
>> Also, Conditional Japanese Starter (CJ,
>> http://www.unicode.org/reports/tr14/proposed.html#CJ) considers
>> half-width variants such as half-width katakana letter small a.
>> -- Makoto

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