- From: Ian B. Jacobs <ij@w3.org>
- Date: Fri, 10 May 2002 12:06:34 -0400
- To: w3c-wai-ua@w3.org
- CC: robla@real.com
Dear UAWG, I received an action item at the 4 April 2002 teleconference [1] to propose some text for the chapter on conformance about "conformance profiles" for other specifications (issue 520 [2]). - Ian [1] http://lists.w3.org/Archives/Public/w3c-wai-ua/2002AprJun/0027 [2] http://www.w3.org/WAI/UA/issues/issues-linear-cr2#520 <PROPOSAL> 3.11 Including UAAG 1.0 requirements in other specifications Authors of technical specifications (such as W3C Recommendations) should incorporate the requirements of UAAG 1.0 as part of conformance to their specifications. This may be done by direct inclusion, or by reference using a conformance profile. Direct inclusion promotes the integration of accessibility requirements; inclusion by reference is easier to do. 3.11.1 General tips 1) Identify accessibility features of the specification where they are defined (see checkpoint 8.1). Optionally, create an appendix of these accessibility features as well. 2) Remember to include user interface requirements as part of conformance to the specification. Authors of technical specifications tend to focus more on rendering or other content-related behavior and less on user interface requirements. UAAG 1.0 makes a number of user interface requirements that authors will need to consider (such as those in Guideline 5 pertaining to viewport behavior). 3) Include a general reference to UAAG 1.0 and Techniques for UAAG 1.0 (see the section "How to refer to UAAG 1.0"). For more information on designing specifications that promote accessibility, refer to WAI's "XML Accessibility Guidelines" [XAG10]. 3.11.2 Direct inclusion of requirements 1) Rather than include the generic UAAG 1.0 requirements, tailor them to the specification. Be specific in the requirement, and include (in context) a reference to the original UAAG 1.0 checkpoint. The following examples illustrate what is meant by direct inclusion: - In an HTML specification, where the SCRIPT, APPLET, and OBJECT elements are defined, include a statement such as "Per checkpoint 3.4 of UAAG 1.0, a conforming user agent must allow configuration not to execute scripts, applets, or other executable content." - In a CSS specification, where the 'text-decoration' property is defined, include a statement such as "A conforming user agent must either: a) allow configuration to override the 'blink' value with the 'none' value, or b) ignore the 'blink' value. This is required by checkpoint 3.3 of UAAG 1.0 [UAAG10]." Note how these examples refer to the specific elements, attributes, properties, etc. of the specifications. 2) Including some UAAG 1.0 requirements in a specification is better than including no requirements. However, since UAAG 1.0 requirements are designed to complement one another, arbitrary selection of requirements may result in accessibility gaps. Authors are encouraged to select requirements in groups defined by the conditional content mechanisms of content, selection, and input modality labels. 3.11.3 Conformance profiles Section G.5 of the SVG 1.0 Recommendation states: "Additionally, an authoring tool which is a Conforming SVG Generator conforms to all of the Priority 1 accessibility guidelines from the document "Authoring Tool Accessibility Guidelines 1.0" [ATAG] that are relevant to generators of SVG content." This statement requires conformance to the Authoring Tool Accessibility Guidelines as part of conformance to SVG 1.0 (for certain classes of tools). This type of "conformance requirement by reference" is also possible for UAAG 1.0. However, since conditional conformance (section 3.2) to UAAG 1.0 can vary beyond three conformance levels, it is important for references to state precisely what is required. This is called a conformance profile. This section explains how to create a valid conformance profile to UAAG 1.0. UAAG 1.0 does not define any (named) conformance profiles, just the mechanism for creating them. A valid conformance profile must include the following information: 1) The guidelines title/version 2) The conformance level required: "A", "Double-A", or "Triple-A". 3) Content type labels: The profile must include at least one content type label (whose requirements must be satisfied). 4) Selection label: The profile must indicate whether a conforming user agent is required to implement a selection mechanism. A valid conformance profile should include the following information: 1) Applicability: Which checkpoints (or portions of checkpoints) do not apply for this specification. For instance, if a specification does not define "tables", the conformance profile should indicate that checkpoint 10.1 does not apply. Specification authors should include rationale in their profiles that explains why a checkpoint does not apply. A valid conformance profile may include the following information: 1) Input modality labels: If conformance for pointer or voice input is required in addition to keyboard input. Note that the following are always required and therefore need not appear in a conformance profile: 1) Keyboard input requirements 2) Content focus requirements (only when the content includes enabled elements; see checkpoint 9.1). The following is an example of a valid conformance profile: <EXAMPLE> "As part of conformance to MyFormat 1.0, a user agent must satisfy the following conformance profile of the "User Agent Accessibility Guidelines 1.0" [UAAG10]: a) Conformance Level A b) Content type labels: VisualText, ColorText, Image, Animation, and Video. This means that a conforming MyFormat user agent must satisfy the requirements associated with those labels; refer to UAAG 1.0 section 3.5 for details. c) Selection: A conforming MyFormat user agent must implement a text selection mechanism, and therefore satisfy the requirements associated with the UAAG 1.0 selection label; refer to UAAG 1.0 section 3.7 for details. A conforming MyFormat user agent is only required to allow users to select text content. d) Applicability: The following UAAG 1.0 checkpoints do not apply to MyFormat and therefore do not need to be satisfied for conformance to this specification: - 1.2, 3.4, 9.5, 9.6: MyFormat does not allow inclusion of scripts. Thus, there are no author-supplied event handlers. - 2.4, 2.6: MyFormat does not involve synchronization. - 2.5, 4.6: MyFormat does not define captions. - 10.1: MyFormat does not define tables. [And so on] </EXAMPLE> Then, in the references section, include the URI of the UAAG 1.0 specification. </PROPOSAL> Notes on the proposal: - I don't think it's necessary to say anything special about mixing formats (e.g., XHTML + MathML + SVG), but I haven't thought about it much. -- Ian Jacobs (ij@w3.org) http://www.w3.org/People/Jacobs Tel: +1 718 260-9447
Received on Friday, 10 May 2002 12:40:05 UTC