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Re: Ideographic Space, word-spacing, and justification

From: Asmus Freytag <asmusf@ix.netcom.com>
Date: Fri, 31 Oct 2008 14:30:07 -0700
Message-ID: <490B78DF.3080105@ix.netcom.com>
To: Steve Deach <sdeach@adobe.com>
CC: Martin Duerst <duerst@it.aoyama.ac.jp>, "KOBAYASHI Tatsuo(FAMILY Given)" <tlk@kobysh.com>, fantasai <fantasai.lists@inkedblade.net>, WWW International <www-international@w3.org>, Paul Nelson <paulnel@winse.microsoft.com>, Michel Suignard <michel@unicode.org>

On 10/31/2008 1:50 PM, Steve Deach wrote:
> Exactly what I said under WSA/WSR. In some languages, this is used for 
> emphasis .
My point was that because they conflict visually, when WSA is used, 
letterspacing should either not be permitted, should be contraction 
only, or should be kept below a threshold that prevents it from being 
confused with WSA.
>
> There are “country” differences, “language” differences, “script”, and 
> “wild hare” (random designer-/instance-specific) differences in 
> everything related to text composition (styling & layout).
Agreed - it is helpful, though, to amass as much detailed input on known 
systematic differences in typical text usage conventions. I find that 
much more helpful than merely saying "watch out - something may depend 
on something".

A./
> (However, 20+ years ago, no one was very careful about those 
> distinctions; so I think I used [or intended to use] script/language 
> in the message below to indicate the distinctions were fuzzy. The same 
> comment applies to “letter”, ”character”, vs. “glyph”; so read my 
> email using the traditional “fuzzy” definitions vs. the current ones.)
>
> On 2008.10.31 12:46, "Asmus Freytag" <asmusf@ix.netcom.com> wrote:
>
> > An aside on "letterspacing":
> >
> > The use of this is language dependent! (Not just script dependent).
> >
> > In German, it the use of increased letterspace for e m p h a s i s
> > (like this) has traditionally been used with both Fraktur and roman
> > style fonts. The practice is apparently still alive and well, because
> > you find it use in electronic forums on the web - a rather modern use of
> > text. Letterspacing, unless kept below very tight thresholds, is
> > therefore c o n f u s i n g to readers expecting it to denote emphasis.
> >
> > Other Northern European languages may have similar issues, but I don't
> > have first hand knowledge of current practices.
> >
> > A./
> >
> > On 10/31/2008 12:04 PM, Steve Deach wrote:
> >> Every few years this issues comes back up. Unfortunately, I can't 
> find the
> >> rather long treatise I wrote the last time.
> >>
> >> In general, I agree with Martin, that one should use styling 
> properties as a
> >> replacement for most of the "layout" uses of space characters (just 
> as one
> >> should use tables in place of most uses of tabs). That said, I would 
> like to
> >> briefly summarize the traditional (pre-DTP) handling of spaces and 
> spacing,
> >> and comment on "what I believe" to be the correct handling.
> >>
> >> Second, I agree that the handling of letterspacing and wordspacing 
> varies by
> >> script and in some cases usage within a script, due to historic/cultural
> >> differences in preferences/aesthetics, or specific readability 
> requirements
> >> for the usage, and the aesthetic desires of the designer.
> >>
> >>
> >>
> >> This is a partial reconstruction of my prior emails on this topic.
> >>
> >> My terminology:
> >> "Spacing" an adjustment to the distance between 2 glyphs/characters.
> >> "Space" a character which has a width but no visible inked 
> representation.
> >> "Letterspacing" an adjustment to the intercharacter spacing used for
> >> line justification. [This definintion differs from CSS's.]
> >> "Wordspacing" an adjustment to the width of an interword space, also
> >> used for line justification.
> >> "WhiteSpaceAddition/Reduction ( WSA/ WSR)" a uniform adjustment to
> >> intercharacter spacing that is applied for design purposes or
> >> emphasis . [This corresponds most closely to the CSS-2.0 definition
> >> of letterspacing. Most DTP applications call this "Tracking".]
> >> "Tracking" and adjustment to intercharacter spacing which varies by
> >> fontsize/pointsize that is used to increase readability when
> >> optical sizing is not provided by the font. [This traditional
> >> definition differs from that used in most DTP applications.]
> >>
> >>
> >> In setting Roman text:
> >> Letterspacing is not generally applied to Arabic (and other
> >> connected-letter scripts/languages, nor to connected letter 
> ("script") faces
> >> in Roman-derivative scripts)
> >> Letterspacing is not generally applied to ideographic or similar
> >> monospaced scripts, nor to monospaced text in Roman-derivative 
> environments.
> >> Traditional applications varied widely in the algorithms used for
> >> weighting how much of a justification adjustment was applied to 
> wordspacing
> >> vs to letterspacing. Most modern systems treat them as 
> linear-proportional.
> >> Traditional publishing applications were also at odds over whether the
> >> letterspacing adjustment AND the wordspacing adjustment should both be
> >> applied to the space/NbSp characters, but most modern systems apply 
> both.
> >> The Unicode NbSp (u+00a0) character should be treated the same as the
> >> Unicode Space (u+0020). [In traditional publishing systems, these are
> >> variable width in justified lines and fixed width in "aligned", 
> tabular, and
> >> math uses. However, some traditional publishing systems treat all space
> >> characters prior to the first non-space in a line as fixed width.]
> >> The FigureSpace (u+2007), and PunctuationSpace (u+2008) are treated the
> >> same way the corresponding figure '0' and punctuation period/full 
> stop would
> >> be treated in the current layout context (justified vs
> >> aligned/tabular/math).
> >> Some traditional publishing systems had a quad-space and a
> >> justifying-space (sometimes called a 'spaceband' rather than 'justifying
> >> space'). Use of the quad-space within justified text would force the 
> fixed
> >> nominal-width of the normal interword space character, disabling
> >> justification adjustments. This encoding concept has no analogy in 
> Unicode.
> >> All other space characters {EM-space, EN, EM-quad, EN-quad, 3/EM, 4/EM,
> >> 6/EM, Thin, & Hair} are treated as fixed width and are not adjusted for
> >> letterspacing nor for wordspacing. (Traditional publishing systems used
> >> these for alignment/layout and did not generally apply tracking nor 
> WSA/WSR
> >> either.)
> >>
> >> Ideographic languages/scripts do not generally use wordspacing or
> >> letterspacing to adjust justification; instead they typically use 
> rules akin
> >> to those described in JIS-4051 (latest). This algorithm involves 
> trimming
> >> some characters to half-width, then reinserting 1/2 & 1/4-em spacing
> >> adjustments at selected points within the line.
> >> Under these rules, Ideographic-space is treated as an ideographic letter
> >> [generally fixed-fullwidth, but has some specific additional rules], 
> and not
> >> as a roman variable space.
> >> It should be a styling option of whether Roman text embedded in
> >> Ideographic text is set using Roman algorithms or Japanese/Chinese
> >> algorithms. Depending on the publication and the publisher, Roman 
> text may
> >> be set proportional (using Roman or Asian justification rules), 
> halfwidth,
> >> or fullwidth. (Similarly, they may choose Asian or Roman 
> word-breaking and
> >> hyphenation rules.)
> >>
> >> I have not covered any specifics in the handling of ancient 
> languages that
> >> are generally only of academic interest; nor the handling of Arabic and
> >> Arabic-dervative scripts; nor Indic; nor certain other language-specific
> >> differences (such as adjustments to spaces on sentence boundaries in 
> some
> >> uses , nor after certain punctuation characters in French and other
> >> languages).
> >>
> >> I have also not addressed the handling of "hanging punctuation" and 
> "hanging
> >> spaces"; though there are different philosophies/algorithm for handling
> >> these across the various script families.
> >>
> >> -- S.Deach
> >> sdeach@adobe.com
> >>
> >>
> >>
> >>
> >>
> >>
> >> On 2008.10.31 02:43, "Martin Duerst" <duerst@it.aoyama.ac.jp> wrote:
> >>
> >>
> >>> 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:-)
> >>>>
> >>>> regards,
> >>>> Tatsuo
> >>>>
> >>>> 2008/10/30 Steve Deach <<mailto:sdeach@adobe.com>sdeach@adobe.com 
> <mailto:sdeach@adobe.com%3Esdeach@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 
> <mailto:fantasai.lists@inkedblade.net%3Efantasai.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
> >>>>>>
> >>>>>>
> >>>>>
> >>>>
> >>>> --
> >>>> KOBAYASHI Tatsuo
> >>>> 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 21:30:56 GMT

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