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RE: BDO example?

From: Jony Rosenne <rosennej@qsm.co.il>
Date: Sat, 16 Aug 2003 15:26:27 +0200
To: <www-international@w3.org>, <bidi@unicode.org>
Message-ID: <000301c363fa$034ce250$0401c80a@QSM4>


I think the HTML specification means that BDO should be used only as the
last resort, when there is no other way to get the bidirectional algorithm
to produce the correct output, or for legacy visual data.

SPAN tells the algorithm that this is a run of characters with a certain
directionality, and in most cases it only affects the neutral characters,
such as space, period or digits, since it does not override the inherent
directionality of the text.

See http://www.w3.org/TR/html401/struct/dirlang.html#h-8.2

Jony


> -----Original Message-----
> From: Tsahi Asher [mailto:tsahi_75@yahoo.com]
> Sent: Saturday, August 16, 2003 1:13 PM
> To: Jony Rosenne; www-international@w3.org; bidi@unicode.org
> Subject: RE: BDO example?
> 
> 
> it is true that in some places in the mozilla.org
> hebrew tech-evangelizm letter, <bdo> can be replaced
> with &rlm;. i found out about &rlm; only after that
> letter was written (my html is not very good).
> 
> on the other side, i'm not sure about the difference
> between <span dir="ltr"> and <bdo dir="ltr">, and when
> will one of them is better used than the other.
> 
> tsahi
> 
> --- Jony Rosenne <rosennej@qsm.co.il> wrote:
> > I'm afraid this isn't a good example, and the
> > rational is incorrect. In all
> > cases the BDO is not necessary. In some places an
> > &rlm; is sufficient, in
> > other cases a <span dir="ltr"> will do.
> > 
> > The use of BDO should be limited to when necessary.
> > HTML 4 specification
> > says:
> > 
> > "The bidirectional algorithm and the dir attribute generally suffice 
> > to manage embedded direction changes. However, some
> > situations may arise when
> > the bidirectional algorithm results in incorrect 
> presentation. The BDO
> > element allows authors to turn off the bidirectional algorithm for 
> > selected fragments of text."
> > 
> > "The BDO element should be used in scenarios where
> > absolute control over
> > sequence order is required (e.g., multi-language
> > part numbers)."
> > 
> > Please note that when you want to say "Document
> > Object Model (DOM)", in a
> > right to left paragraph the acronym follows on the
> > left within rtl
> > parentheses.
> > 
> > The sample given also has an error in the meta tag.
> > 
> > A corrected version, without BDO, is at
> > http://www.qsm.co.il/Hebrew/nobdo.htm
> > 
> > Jony
> > 
> > > -----Original Message-----
> > > From: www-international-request@w3.org 
> > > [mailto:www-international-request@w3.org] On
> > Behalf Of
> > > bidi@prognathous.mail-central.com
> > > Sent: Saturday, August 16, 2003 10:31 AM
> > > To: ishida@w3.org; www-international@w3.org
> > > Subject: RE: BDO example?
> > > 
> > > 
> > > 
> > > Here's an example:
> > >
> >
> http://www.mozilla.org/projects/tech-evangelism/site/tech-lett
> > > er-he.html
> > > You can read the rational for the use of BDO here:
> > 
> > >
> >
> http://bugzilla.mozilla.org/show_bug.cgi?id=99578#c14
> > > 
> > > Prog.
> > > 
> > > On Fri, 15 Aug 2003 22:30:04 +0200, "Jony Rosenne"
> > 
> > > <rosennej@qsm.co.il>
> > > said:
> > > > 
> > > > I have used it for imbedding legacy data from an
> > IBM
> > > mainframe, which
> > > > uses visual encoding, in HTML. I suppose this is
> > the most
> > > common use
> > > > today, because there is quite a lot of legacy
> > Hebrew data out there.
> > > > 
> > > > The original example which I gave many years ago
> > and helped
> > > convince
> > > > Unicode that an override was required was a
> > reference number, or a
> > > > part number, which looks like a random groups of
> > digits, Hebrew
> > > > letters and Latin letters
> > > > with slashes between them, which are often used
> > in
> > > correspondence. When
> > > > we
> > > > still used typewrites, back in the previous
> > century, people
> > > could type
> > > > any
> > > > odd combination they fancied.
> > > > 
> > > > Jony
> > > > 
> > > > > -----Original Message-----
> > > > > From: www-international-request@w3.org
> > > > > [mailto:www-international-request@w3.org] On
> > Behalf Of
> > > Richard Ishida
> > > > > Sent: Friday, August 15, 2003 9:03 PM
> > > > > To: www-international@w3.org
> > > > > Subject: BDO example?
> > > > > 
> > > > > 
> > > > > 
> > > > > Does anyone have a convincing example of the
> > need for BDO
> > > > > markup in HTML for Arabic or Hebrew?
> > > > > 
> > > > > I already have an example of 'this is what the
> > text looks
> > > > > like in memory', but that is not very
> > mainstream.  I don't
> > > > > really want an example that allows the support
> > of visually
> > > > > encoded text, either.
> > > > > 
> > > > > Successful proposers may expect to see their
> > example used as
> > > 
> > > > > an illustration in the XHTML 2.0 spec and in
> > GEO guidelines.  ;)
> > > > > 
> > > > > Thanks in advance,
> > > > > RI
> > > > > 
> > > > > ============
> > > > > Richard Ishida
> > > > > W3C
> > > > > 
> > > > > tel: +44 1753 480 292 http://www.w3.org/People/Ishida/
> > > > > http://www.w3.org/International/ 
> > > > > http://www.w3.org/International/geo/
> > > > > 
> > > > > See the W3C Internationalization FAQ page
> > > > > http://www.w3.org/International/questions.html
> > > > > 
> > > > > 
> > > > > 
> > > > > 
> > > > 
> > > > 
> > > > 
> > > 
> > > 
> > 
> > 
> 
> 
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Received on Saturday, 16 August 2003 08:28:42 GMT

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