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SC 1.3.1 and Low Vision

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After more discussion on issues surrounding WCAG 2.0 SC 1.3.1 and WCAG's coverage of the needs of users with low vision, we propose an interim solution that would provide for publication of the updated Techniques and Understanding documents soon, while we continue to discuss the larger issue for potential later edits.

Our recommendations for now would be to:

1) revert and edit part of the draft edits to G140 [1] - see details below under "RECOMMENDED EDITS TO G140";

2) publish the pending updated Techniques and Understanding, without additional edits or clarifications related to SC 1.3.1;

3) leave Shawn's comment about GL 1.3 [2] listed as "unresolved" with this publication;

4) plan for discussions on the broader issue, hopefully leading to more specific suggestions.


In reviewing G140 of the Editors' Drafts of the updated Techniques and Understanding documents, we noticed new content for Technique G140 [1] apparently intended to address part of the issue raised by Shawn in her comment [3]. However, in light of the other unresolved concerns, these edits seem more likely to complicate rather than to help the issue at this stage.

For one thing, it seems that ClaroRead does not read structural markup (tags) from PDF and does not provide structural markup in converted HTML, Word, or "ClaroPDF" files. Therefore, it seems that ClaroRead does not currently provide the functionality that is described in the following phrasing "ClaroRead displays PDF by transforming it to an HTML document, using the PDF tags as the basis for the structure of the HTML."

In order to avoid misunderstandings about support relevant to SC 1.3.1, we therefore recommend the following changes to the Editors' Draft before publication:

1. Until we address the larger issue, revert the sentence in the middle of the "description" section that currently states "Examples of ways in which user agents can use structural information to transform the presentation of the content include..." back to the previous text which stated "Following this technique allows user agents to:";

2. Remove ClaroRead from the Resources section (unless there is something we missed about its functionality related to this technique. We are happy to discuss this point to get a better shared understanding of the tool);

3. Edit and move Example 2: Tagged PDF. Remove the last sentence of Example 2, and, in the middle sentence, remove the phrase "and different viewers." This would leave:

"A PDF document consists mostly of the content embedded with formatting information. Information about the structure is provided in a separate section of the document using XML-like tags; this is called "tagged PDF". The information in these tags can be used by assistive technologies to perform meaningful structure transformations (e.g., generating a list of sections) or to support interaction with content based on structural characteristics (e.g., jumping to the start of forms)."

The remaining text then actually seems to focus more on navigation; therefore we recommend moving the remaining parts of this example to a more appropriate navigation-related SC or to Guideline (see suggestions below at [4]).


- Judy and Shawn

[1] Editors' Draft of G140

[2] Comment about GL 1.3 (or more specifically SC 1.3.1)

[3] SLH's comment on Techs G140 example <>

[4] Nav-related topic- perhaps: