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Re: Ideographic Space, word-spacing, and justification

From: Martin Duerst <duerst@it.aoyama.ac.jp>
Date: Fri, 31 Oct 2008 18:43:50 +0900
Message-Id: <>
To: "KOBAYASHI Tatsuo(FAMILY Given)" <tlk@kobysh.com>, "Steve Deach" <sdeach@adobe.com>
Cc: fantasai <fantasai.lists@inkedblade.net>, "WWW International" <www-international@w3.org>, "Paul Nelson" <paulnel@winse.microsoft.com>, "Michel Suignard" <michel@unicode.org>

Hello everybody,

Just a bit of a wider background on full-width space.

It should be remembered that in contrast to the usual space (U+0020),
which occurs all over the place in texts in most languages, the
full-width space doesn't occur AT ALL in typical Japanese (or Chinese)
texts. That's why it also barely occurs in the document written
by the Japanese Layout TF, as well as in JIS 4501.

The full-width space is more used for layout than inside the actual
text. In this respect, what CSS should do is to mainly look at
Japanese typography and try to come up with properties that allow
to get rid of full-width spaces in the text, rather than spending
too much time on how to treat full-width space.

As a typical example, I guess lead typesetting and also definitely
simple approaches to typesetting on the computer, such as plain
text or old "word-processors" (which were not very much above
plain text in their capabilities) use a full-width space to produce
a start-of-paragraph indent (which is very often one full-width
character wide). CSS should make sure that there is no need to
insert such full-width spaces, because an exact one-full-width-
character start-of-paragraph indent can be produced with an
appropriate CSS property setting.

Another typical use of full-width space was to center text,
and to insert spaces into text for headlines (to a large
extent a crude backup for increasing text size, which wasn't
possible when technology was limited to one or two bit-mapped
font sizes. In this case, inter-character spacing property(/ies)
may be important for 'facsimile' layouts, but with modern
technology, such layout isn't much used anymore anyway.

Regards,   Martin.

At 18:31 08/10/30, KOBAYASHI Tatsuo(FAMILY Given) wrote:
>Hi, Erica,
>In Japanese Layout, "spacing issue" is one of the most difficult issues to treat.
>We intended to carefully eliminate concrete character name like IDEOGRAPHIC SPACE(U+3000) and SPACE(U+0002) from our requirement. Rather introduced three different types of abstract space concepts as follows:
>inter character space: usulal 1/2 em fixed space.
>conditional space: 1/2 em fixed space to be inserted or pulled off between characters and punctuation marks.  
>adjustable space: variable width space, behaves like usual western variable space.
>Note that, usual Japanese punctuation marks have 1/2 em width in our requirement, even if the character name might include "FULLWIDTH ~~~"
>Anyway, the disition how to deal with these spaces in CSS recommendation and in actual implementation is up to your side:-)
>2008/10/30 Steve Deach <<mailto:sdeach@adobe.com>sdeach@adobe.com>
>>No, in my personal opinion, it should not.
>>The 2 differences between normal space/nbsp vs ideographic space are:
>> 1.) The normal width is different, and
>> 2.) The normal space/nbsp is treated as justifying
>>     (adjusted by both wordspacing and letterspacing),
>>     whereas the Ideographic space should only be adjusted by
>>     letterspacing (only if ideographic letters are also so adjusted).
>>However, I will re-confirm this with our CJK experts, before claiming this
>>is an Adobe opinion.
>>On 2008.10.29 15:13, "fantasai" <<mailto:fantasai.lists@inkedblade.net>fantasai.lists@inkedblade.net> wrote:
>>> Hello,
>>> The CSSWG would like to know whether the IDEOGRAPHIC SPACE U+3000
>>> should be affected by 'word-spacing', and whether it should be
>>> treated as a space during spaces-only justification or treated as
>>> a typical ideographic punctuation character.
>>> ~fantasai
>Scholex Co., Ltd. Yokohama
>JUSTSYSTEM Digital Culture Research Center

#-#-#  Martin J. Du"rst, Assoc. Professor, Aoyama Gakuin University
#-#-#  http://www.sw.it.aoyama.ac.jp       mailto:duerst@it.aoyama.ac.jp     
Received on Friday, 31 October 2008 09:55:32 UTC

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