Glossary entry for Essential. WAS: Should the boxes around blocks of text in the FPWD have Sufficient contrast under the new SC. WAS: Re: CFC: Publish WCAG 2.1 FPWD

I noticed there are also two versions of the glossary entry for “essential” linked in the 2.1 draft, with some instances of “essential” pointing to the proposed glossary definition (which includes two new examples), and some pointing to the original WCAG 2.0 definition.

For example, existing 1.4.5 points to the new, within document glossary entry and proposed 1.4.14 points to the original glossary entry in WCAG 2.0 (out of document).

This may be true for other entries, but I haven’t checked.

In looking at the proposed entry for essential examples, they seem incomplete at this stage.   I want to +1 Jason White’s earlier comment in the FPWD CFC thread regarding the need in the FPWD to emphasize that glossary entries are present under the same cautionary terms as the Proposed SC.


From: David MacDonald []
Sent: Thursday, February 23, 2017 9:09 AM
To: Gregg Vanderheiden RTF <>
Cc: Michael Gower <>; Alastair Campbell <>; Mike Elledge <>; w3c-waI-gl@w3. org <>
Subject: Re: Should the boxes around blocks of text in the FPWD have Sufficient contrast under the new SC. WAS: Re: CFC: Publish WCAG 2.1 FPWD

>I cringe whenever I see  ‘essential’ in a rule.

oh oh... there are a lot of "essential" instances in SCs There are 3 SCs with it in WCAG 2, and 9 in the proposed SCs for 2.1. This would be a good time to discuss alternatives.


1.4.9 Images of Text (No Exception)§AAA
​ ​
Images of text are only used for pure decoration or where a particular presentation of text is essential to the information being conveyed.
2.2.1 Timing Adjustable
​ ​
​ ​
Essential exception
2.2.3 No Timing§AAA
​ ​
Timing is not an essential part of the event or activity presented by the content, except for non-interactive synchronized media and real-time events.


WCAG 2.1
1.4.10A mechanism is available to view content as a single column, except for parts of the content where the spatial layout is essential to the function and understanding of the content.
1.4.12 Graphics Contrast
The visual presentation of graphical objects that are essential for understanding the content or functionality have a contrast ratio of at least 4.5:1 against the adjacent color(s), except for the following:
1.4.14 User Interface Component Contrast (Minimum)
The visual presentation of essential graphical objects for user interface component(s)
2.2.7 Animation from interactionsA
For significant animations triggered by a user action that is not an essential part of the action, there is a mechanism for the user to pause, stop or hide the animations while still performing the same action.
2.6.1 Device Sensors
All functionality of the content can be operated without requiring specific device sensor information unless the device sensor is essential for the function and not using it would invalidate the activity2.6.2 Orientation§
2.6.2 Orientation: Content is not locked to a specific orientation, and functionality of the content is operable in all orientations, except where orientation is essential for use of the content.
3.1.7 Plain Language (Minimum) Essential exception: If the writing style is an essential part of the main function of the site, such as a game, a literary work, or teaching new terms.
3.2.6 Accidental Activation
​ essential exception:  Timing of activation is essential and waiting for the up-event would invalidate the activity.
3.2.7 Familiar design essential Exception: The style is an essential part of the main function of the site, such as for a game

David MacDonald

CanAdapt Solutions Inc.

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On Thu, Feb 23, 2017 at 6:28 AM, Gregg Vanderheiden RTF <<>> wrote:

​- ​
an alternative
​means of visually displaying
 the essential information
​ is provided. (e.g., visible text)

I cringe whenever I see  ‘essential’ in a rule.

1) there is no way to judge essential
2) there is a long history of this term being abused by developers to not include things you would judge as essential.

for example — on phones — only the dial pad is essential.   not being able to look things up in the directory of phone numbers on your phone.  or anything else on your phone.

on a web page — only the primary function of the page is essential.   all the rest is extra


and worse.

Essential is not objective


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Received on Thursday, 23 February 2017 16:44:32 UTC