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Re: Action-902 Units of measure for 1.4.3

From: Jim Allan <jimallan@tsbvi.edu>
Date: Mon, 7 Oct 2013 16:38:02 -0500
Message-ID: <CA+=z1WkR8iLYsQ6vpf9DA1YSaFJcNBQm-nTBvp_uO+5yRXT_hg@mail.gmail.com>
To: Jeanne Spellman <jeanne@w3.org>
Cc: UAWG <w3c-wai-ua@w3.org>
References (for 1.4.3 in IER)
http://www.w3.org/TR/CSS2/visudet.html#leading
 http://www.w3.org/wiki/CSS/Properties/line-height
http://www.w3.org/TR/CSS2/text.html#spacing-props
http://www.w3.org/TR/CSS2/fonts.html#font-styling
http://www.w3.org/TR/CSS2/fonts.html#font-boldness
http://www.w3.org/TR/CSS2/text.html#lining-striking-props
http://www.w3.org/TR/CSS2/text.html#alignment-prop

Table of all CSS properties http://www.w3.org/TR/CSS2/propidx.html

adding a Note to 1.4.3
Note: The unit of measure will vary by the technology. For the purposes of
UAAG 2.0, the font height should be considered to be equal to 1. The font
width of the character M (or other character commonly accepted in the
typography for that language) should be considered to be equal to 1.

<jim in the note, 0 was confusing (as it is a zero, not an O), I changed to
an M
I added the word and character spacing, justification, bold, etc references>

any other comments, additions, smithing???


On Fri, Oct 4, 2013 at 2:22 PM, Jeanne Spellman <jeanne@w3.org> wrote:

> As per my action item, I followed up on the text customization proposal to
> see what unit of measure was intended for 1.4.3 on line height (leading),
> character and word spacing.
>
> Results:  No unit of measure was specified deliberately, because no unit
> of measure is proper usage. Examples were given of CSS and Word, which both
> accept a number without a unit of measure.
>
> I personally disagree with this. While my typography experience is quite
> dated, I have always used a unit of measure in typography.  While this (no
> unit of measure) is allowed in CSS, the examples make clear that CSS2
> considers no unit of measure as em. The calculation of line-height in CSS
> 2.1 is quite complex, and I think we should avoid it ourselves, and refer
> people to appropriate documentation.
> http://www.w3.org/TR/CSS2/**visudet.html#leading<http://www.w3.org/TR/CSS2/visudet.html#leading>
>
> References (which I think we should include in the References section of
> 1.4.3 IER)
> http://www.w3.org/TR/CSS2/**visudet.html#leading<http://www.w3.org/TR/CSS2/visudet.html#leading>
>  http://www.w3.org/wiki/CSS/**Properties/line-height<http://www.w3.org/wiki/CSS/Properties/line-height>(some useful language here, IMO.)
> Table of all CSS properties http://www.w3.org/TR/CSS2/**propidx.html<http://www.w3.org/TR/CSS2/propidx.html>
> The spec for CSS3 is not complete and should not be referenced.  The
> latest working draft (for your info) is http://www.w3.org/TR/css3-**
> text/#word-spacing <http://www.w3.org/TR/css3-text/#word-spacing>
>
> I propose adding a Note to 1.4.3
> Note: The unit of measure will vary by the technology. For the purposes of
> UAAG 2.0, the font height should be considered to be equal to 1. The font
> width of the character 0 (or other character commonly accepted in the
> typography for that language) should be considered to be equal to 1.
>
>


-- 
Jim Allan, Accessibility Coordinator & Webmaster
Texas School for the Blind and Visually Impaired
1100 W. 45th St., Austin, Texas 78756
voice 512.206.9315    fax: 512.206.9264  http://www.tsbvi.edu/
"We shape our tools and thereafter our tools shape us." McLuhan, 1964
Received on Monday, 7 October 2013 21:38:26 UTC

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