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Re: [css21-media-types] [css3-speech] normative media types, mutual-exclusivity

From: Daniel Weck <daniel.weck@gmail.com>
Date: Fri, 10 Dec 2010 21:41:08 +0000
Message-Id: <3CD666E6-2502-4BB1-BF98-68703CCE43D1@gmail.com>
To: www-style@w3.org, fantasai <fantasai.lists@inkedblade.net>

On 10 Dec 2010, at 20:13, fantasai wrote:
> The CSS3 Syntax module is severely unmaintained. Please ignore its
> existence. :) The only dependency CSS3 Speech should have is CSS2.1.

Thanks for your reply Fantasai.
However, as you probably know section "7.1.4. Recognized media types"  
from CSS3-Syntax [1] (which I am concerned about) is near-identical to  
section "7.3. Recognized media types" from CSS 2.1 [2], in fact the  
exact ambiguous prose I referred to is there too. So both of my  
questions still stand, and I have updated the email title to match ;)
Regards, Dan



My full original email is quoted for reading convenience:

On 10 Dec 2010, at 18:44, Daniel Weck wrote:

> Hi all,
> I am in the process of completing a review of the CSS3 Speech Module  
> and its related dependencies, and I came across general statements  
> that seems ambiguous to me. Please correct me if I'm wrong.
> In section "7.1.4. Recognized media types" of the CSS-Syntax  
> specification [1], the following normative statement is pretty clear  
> (note the "MUST"):
> "A CSS media type names a set of CSS properties. A user agent that  
> claims to support a media type by name must implement all of the  
> properties that apply to that media type. ... The names of media  
> types are normative."
> So for example, let's take the CSS-Speech Module [2]: conforming  
> user agents (e.g. web-browsers with screen-reader support) must  
> implements all of the CSS Properties marked with the "speech" media  
> type. To me, this means that the "Media" field in the description of  
> each CSS Property has a critical normative value: it is the only way  
> for implementors to know, without ambiguity, what properties MUST be  
> handled in order to claim conformance as a user-agent supporting  
> speech-synthesis.
> The same remark obviously applies to any other CSS Property, for any  
> other media type normatively specified in CSS3 (e.g. visual,  
> braille, print, etc.).
> Yet, in the same section "7.1.4" we read:
> "the 'Media' field in the description of each property is  
> informative."
> I would have thought that this should be "normative", not  
> "informative". Could one of the CSS-Syntax editors please clarify  
> this ?
> Additionally, section "7.1.4" also states:
> "Media types are mutually exclusive in the sense that a user agent  
> can only support one media type when rendering a document."
> This statement is not problematic in itself, but section "2.  
> Introduction" of the CSS-Speech Module seems to be make a  
> contradictory assertion:
> "Style sheet properties for text to speech may be used together with  
> visual properties (mixed media)"
> Any thoughts ?
> Thank you :)
> Regards, Daniel
> [1]
> http://www.w3.org/TR/css3-syntax/#media
> [2]
> http://www.w3.org/TR/css3-speech/#property-index

Daniel Weck
Received on Friday, 10 December 2010 21:41:52 UTC

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