- From: Jeanne Spellman <jeanne@w3.org>
- Date: Fri, 04 Oct 2013 15:22:25 -0400
- To: UAWG <w3c-wai-ua@w3.org>
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 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/wiki/CSS/Properties/line-height (some useful language here, IMO.) Table of all CSS properties 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 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.
Received on Friday, 4 October 2013 19:22:30 UTC