ChangeProposals/ImgElementSurveyConformaceChoices

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Change Proposal Choices for Alt ISSUE 31

Alt Issue-31 encompasses three areas/is about three questions regarding the img element:

  1. Guidance for conformance checkers: "Which set of validity requirements should HTML5 adopt?"
  2. The <img> element definition verbiage: "What verbiage should HTML5 use for the first two paragraphs of the img element definition?"
  3. Text alternative examples and their values: "Where/who will define requirements on the possible values of text alternatives examples?"

1. Guidance for Conformance Checker Question: "Which set of validity requirements should HTML5 Adopt?"

Part of Issue-31 involves what to do about validation when the image element is missing the alt attribute. Change proposals 1, 2, 3, 4, 5, and 6 delineate distinct sets of requirements for survey.

Conformance Checker Proposals: Validity requirements Sets
Validity Option Requirement Set 1 Requirement Set 2 Requirement Set 3 Requirement Set 4 Requirement Set 5 and Requirement Set 6
Aria-labelledby Disallows Allows Allows Disallows Disallows
Role attribute with a value of "presentation" Disallows Allows Disallows Disallows Disallows
Generator mechanism Allows Disallows Disallows Disallows Disallows
Email exception Allows Disallows Disallows Disallows Disallows
Title attribute Allows Disallows Disallows Disallows Disallows
Figcaption Allows Allows Allows Allows Disallows

Note: Issue-80 Change proposal also disallows the title attribute.

Conformance Checker Proposals: Rationale and Spec Text
Proposal 1 Proposal 2 Proposal 3 Proposal 4 Proposals 5 and 6
Rationale Proposal 1 Conformance Checker Rationale Proposal 2 Conformance Checker Rationale Proposal 3 Conformance Checker Rationale Proposal 4 Conformance Checker Rationale Proposal 5 Conformance Checker Rationale and Proposal 6 Conformance Checker Rationale
Suggested Spec Text

A conformance checker must report the lack of an alt attribute as an error unless one of the conditions listed below applies:

  • The title attribute is present and has a non-empty value (as described above).
  • The img element is in a figure element that contains a figcaption element that contains content other than inter-element whitespace (as described above).
  • The conformance checker has been configured to assume that the document is an e-mail or document intended for a specific person who is known to be able to view images.
  • The document has a meta element with a name attribute whose value is an ASCII case-insensitive match for the string "generator". (This case does not represent a case where the document is conforming, only that the generator could not determine appropriate alternative text - validators are required to not show an error in this case to discourage markup generators from including bogus alternative text purely in an attempt to silence validators.)

A conformance checker must report the lack of a text alternative as an error. The image element <img> is only valid when at least one of the following is true. The

  • alt attribute is present (empty or non-empty), or
  • aria-labelledby attribute present (non-empty only), or
  • <img> element is located within a <figure> element that has a non-empty <figcaption> element, or
  • role attribute is present and has a value of "presentation".

A conformance checker must report the lack of an alt attribute as an error unless one of the conditions listed below applies:

  • the <img> element is located within a <figure> element that has a non-empty <figcaption> element, or
  • a non-empty aria-labelledby attribute is present.
A conformance checker must report the lack of an alt attribute as an error unless the <img> element is located within a <figure> element that has a non-empty <figcaption> element. A conformance checker must report the lack of an alt attribute on the <img> element as an error.

2. <Img> Definition Question: "What verbiage should HTML5 use for the first two paragraphs of the img element definition?"

Proposals 1, 5, 6 and 7 suggest verbiage to be used as spec text for the first two paragraphs of the <img> element definition. The following delineates these options.

<Img> Definition Proposals: Rationale and Spec Text
Proposal 1 Proposal 5 Proposal 6 Proposal 7
Rationale Proposal 1 Definition Rationale Proposal 5 Definition Rationale Proposal 6 Definition Rationale Proposal 7 Definition Rationale
Suggested Spec Text

An img element represents an image.

The image given by the src attribute is the embedded content, and the value of the alt attribute is the img element's fallback content.

An img element represents an image.

The image given by the src attribute is the embedded content, and the value of the alt attribute is text content that is rendered when the image is not displayed by a User Agent.

The <img> element represents content that can be rendered visually (as an image) and textually.

The src attribute provides visual content in the form of an image and the alt attribute provides textual content. The content in the src and alt attributes must convey equivalent meaning.

An img element represents an image.

The image given by the src attribute is the embedded content; the value of the alt attribute provides equivalent content for those who cannot process images or who have image loading disabled.

3. Text Alternative Examples Question: "Where/who will define requirements on the possible values of text alternatives examples?"

Proposals 1, 8, and 9 address text alternative examples and their values. The following delineates change proposals for survey on where/who will define requirements on the possible values of text alternatives examples.

Text Alternative Examples Proposals: Rationale and Suggested Action
Proposal 1 Proposal 8 Proposal 9
Rationale: Where/who will define requirements on the possible values Proposal 1 Rationale: Where/who will define requirements on the possible values Proposal 8 Rationale: Where/who will define requirements on the possible values Proposal 9 Rationale: Where/who will define requirements on the possible values
Suggested Action Let requirements on the possible values of the text alternatives be defined by the current text in HTML5. Let requirements on the possible values of the text alternatives be defined by "Techniques for providing useful text alternatives". (Either by direct text replacement of current HTML5 text or removal of HTML5 text and replacement with a link to the "Techniques for providing useful text alternatives" document .) Let requirements on the possible values of the text alternatives be defined by WCAG 2.0

Note*: Both Issue Issue-31 and Issue-122 concern text alternative values examples in the <img> element design space. Issue-122's scope was expanded to apply to all WG deliverables.

Proposals and Options by Listing

Proposal 1

  • Disallows aria-labelledby.
  • Disallows role attribute with a value of "presentation".
  • Allows generator mechanism.
  • Allows email exception.
  • Allows title attribute.
  • Allows figcaption.
  • Allows image definition to remain as is. (alt as fallback; alternative text is not a first-class citizen.)
  • Lets requirements on the possible values of the text alternatives be defined by the current text in HTML5.

Proposal 2

  • Allows aria-labelledby.
  • Allows role attribute with a value of "presentation".
  • Disallows generator mechanism.
  • Disallows email exception.
  • Disallows title attribute.
  • Allows figcaption.
  • No mention of <img> definition.
  • No mention of the examples.

Proposal 3

  • Allows aria-labelledby.
  • Disallows role attribute with a value of "presentation".
  • Disallows generator mechanism.
  • Disallows email exception.
  • Disallows title attribute.
  • Allows figcaption.
  • No mention of <img> definition.
  • No mention of the examples.

Proposal 4

  • Disallows aria-labelledby.
  • Disallows role attribute with a value of "presentation".
  • Disallows generator mechanism.
  • Disallows email exception.
  • Disallows title attribute.
  • Allows figcaption.
  • No mention of <img> definition.
  • No mention of the examples.

Proposal 5

  • Disallows aria-labelledby.
  • Disallows role attribute with a value of "presentation".
  • Disallows generator mechanism.
  • Disallows email exception.
  • Disallows title attribute.
  • Disallows figcaption.
  • Changes the image definition ala HTML4.
  • No mention of the examples.

Proposal 6

Proposal 7

  • No mention of aria-labelledby.
  • No mention of role attribute with a value of "presentation".
  • No mention of generator mechanism.
  • No mention of email exception.
  • No mention of title attribute.
  • No mention of figcaption.
  • <img> definition: Change: A Variation of Proposals 5 and 6
  • No mention of the examples.

Proposal 8

Proposal 9

Details and History of Proposals

Details and History of Proposals