+1

I added this one to the QA checklist yesterday :) I think only the first usage of a term in a given SC should be linked to the definition.

once a page would be fine, don't clutter the page with redundant links for multiple A11Y reasons.

My proposal is once per SC, not once per page. All of WCAG 2.1 is one page, and I think that's insufficient, people would read many SC without having seen the term linked previously, and not know there is a term. So I think SC should be standalone in that sense, all the terms needed for understanding of an SC should be referenced from the SC even though that means the term is referenced multiple times on the page as a whole. But I do agree (and why I filed this issue) that cluttering a given SC with more than one link to a particular term doesn't add value, and probably reduces it.

+1 for per SC as these are all one page (didn't take that into account)

In such a case one might think the term should be referenced, yet the definition doesn't seem targeted to the meaning of the word in all SC.

@michael-n-cooper, I think you're right and we should check all uses of "essential", but part of the problem here might be that the definition of essential seems to have been inadvertently changed from 2.0 to 2.1 as mentioned in #333. A commit for the Orientation SC likely did this and we should reverse it and either discard changes or move the excess information to a note for that criterion.

The definition of "essential" didn't inadvertently change from 2.0 to 2.1, it was deliberately changed, when we accepted the SC "Orientation". As part of the normalization process we're now in we should review if that change works for the other uses of the term, and decide what to do if not. I just want to clarify it wasn't inadvertent.

Also note the change of the definition for "essential" is a separate (though related) issue to the one filed here. The issue here is whether unlinked uses of the term should be linked, if not why not, and if there is something that needs to be done to the term to make adding such links work, what? The decision on that would be impacted by what we do with #333 as mentioned above and vice versa, but they are separate issues that I think it will be clearer to handle as separately as possible.

I agree the change to the definition of "essential" is a separate issue from this one, but I would not agree it was deliberate in the sense that consensus was given by the working group to make such a change. It would have been easy to miss in a review given that it is not documented in the proposal for #70 (I certainly missed it), and the conclusion from yesterday's meeting was that a pretty high bar exists for changing existing criteria, which includes their glossary references.

My analysis is that the glossary definition of essential presumes that the word is being used in an exception, primarily driven by the second clause requiring an evaluation of whether or not it could be achieved in a way that conforms.

The following criteria use the word correctly as an exception, but do not link to the glossary:

• Graphics Contrast (the exception, not the main text)
• Pointer Gestures
• Concurrent Input Mechanisms
• Device Sensors

Each of these could be fixed by simply adding the link, although one could argue a few cases for slight wording changes to avoid discrepancy with the glossary.

And the following criteria use the word outside of an exception which can lead to confusion:

• Graphics Contrast (to describe graphical objects)
• User Interface Component Contrast (to describe visual identifiers)
• Adapting Text (to describe content that cannot be lost)
• Content on Hover or Focus (to describe content of the trigger which cannot be obscured)
• No Timing (to describe the timing - yes and 2.0 SC uses it incorrectly)
• Accessible Authentication (to describe steps in a process)
• Animation from Interactions (technically, this is a correct usage since it's qualifying "non-essential" animations, but could be stated less awkwardly)

For each of these, I think the solution may be a bit different. Some could probably just eliminate the word as unnecessary, while others need to formulate it as an appropriate exception. We should dig through each to see where "essential" was introduced.

Follow up from my previous comment with more detail and proposals...

Correct Usage of Essential

Upon further review, all 4 of the above criteria - Graphics Contrast (exception only), Pointer Gestures, Concurrent Input Mechanisms, and Device Sensors - use the term properly in an exception. I believe they can all safely just be linked to the glossary as purely an editorial change.

Incorrect Usage of Essential

The following criteria are currently using "essential" incorrectly because it is not describing something that is exempt from the respective criterion. Possible fixes for each are discussed separately.

Graphics Contrast

This criterion restricts applicability to "graphical objects that are essential for understanding the content or functionality". I see two possible solutions here:

1. Replace "essential" with an appropriate synonym such as "required", and explain what that means in the Understanding docs (as is being done now).
2. If we truly need to harness part of the definition of essential, then go back to simply saying "graphical objects" and provide a definition which explains that purely decorative stuff is not included.

User Interface Component Contrast

This criterion restricts its applicability to "essential visual identifiers". Given that the notes and Understanding are going into detail about what that means and it is not tied to the definition, I would recommend we just strike the word "essential" from this phrase everywhere. My logic is that saying "essential" is mostly redundant with the word "identifier", i.e. if something visual is identifying the type of component or its state, then it is always essential.

Adapting Text

The criterion refers to "no loss of essential content or functionality". The word seems to have been introduced by @awkawk in a comment way back in March, but I could not find any rationale for its inclusion in the language (i.e. an example of content loss that would be acceptable). Given this, and the fact that both Resize Text and Zoom Content refer to "loss of content or functionality" without using essential, I propose to simply remove the word from this SC.

Content on Hover or Focus

This criterion says that the additional content should not "obscure any essential content within the trigger". The use here is meant to say that decorative content is okay to obscure, so I recommend a rewording which links to the definition of "pure decoration" instead.

No Timing

Yes, an existing AAA criterion is using "essential" incorrectly. However, it is clear to me from the SC that this is simply meant to be a synonym for "required", and the Understanding content even just says required and gives no rationale for using "essential". I recommend we replace "essential" with "required" as WCAG 2.0 errata and merge into 2.1.

Accessible Authentication

This criterion restricts the applicability to "essential" steps, but it appears to me that this is really meant as a synonym for "required" steps. The 2nd use in the bullet I believe is unnecessary to the SC. So, I propose simply replacing "essential" with "required" to correct the former misuse and delete the latter use.

Animation from Interactions

This criterion is actually using the term correctly as an exception to restrict applicability to "non-essential animations", but it's an awkward read. I would recommend just moving the clause to a clear exception at the end such as:

Animation from Interactions: For animations triggered by a user action, there is a mechanism to disable the animations yet still perform the action, unless the animation is essential.

I believe the word "essential" is needed, helpful and understandable as it currently sits in all of these proposed SC. I do not agree that "essential" can only be used when discussing an exception.

I believe the word "essential" is needed, helpful and understandable as it currently sits in all of these proposed SC. I do not agree that "essential" can only be used when discussing an exception.

Hi @goodwitch. To understand why it can only be applied to exempt content, let's break down the definition:

if removed, would fundamentally change the information or functionality of the content, ...

I believe you desire to use only this part of the definition, which I would agree has no restrictions to exceptions. However, it does kind of imply it's analyzing an exemption by saying "if removed". If harnessing this clause is truly necessary, then we need to break out the 2nd clause, or alternatively exempt things like "pure decoration".

... and information and functionality cannot be achieved in another way that would conform

This clause is the primary problem; it directly states that the "essential" adjective is describing something that does not currently conform. So, if we take "essential visual identifiers" as an example from the UI Contrast SC, it simply doesn't make sense. It's basically saying evaluate the criterion for visual identifiers that currently don't conform.

@steverep I see what you are saying now! Sorry it took me so long to grok that! You are right. The phrase "and information and functionality cannot be achieved in another way that would conform" makes it illogical.

And in looking deeper, I think you are right that the phrase "essential visual identifier" does not need the word "essential"...because the word "identifier" is enough. That would solve the problem in 1.4.12 User Interface Component Contrast (Minimum)

In one last review before I submit a pull request, it looks like I missed a 5th correct usage of essential that is perfectly valid but not linked in Accidental Activation.

Posting this to aid further discussion of this issue as survey and call minutes still reflect ties to only the 1st half of the "essential" definition.

Substituting the Definition of Essential

Here is the 2nd half of the definition substituted into the SC still under debate. Please, oh please, tell me how any of these make logical sense. Assuming you cannot make sense of it like me, then if you don’t like my proposal for a particular criterion, then propose something else that either uses “essential” correctly or omits it. I’d be happy to create and debate multiple options when backed up with sound arguments for exceptions, but leaving these as they are now in the draft is terribly confusing.

Adapting Text

If the technologies being used allow the user agent to adapt style properties of text, then no loss of content or functionality (which cannot be achieved in another way that would conform) occurs by adapting all of the following: ...

Content on Hover or Focus

... Visible Trigger: Either the additional content does not obscure any content (whose information and functionality cannot be achieved in another way that would conform) within the triggering user interface component, or the additional content can be closed or repositioned by the user; ...

Graphics Contrast

The visual presentation of graphical objects that (cannot be achieved in another way that would conform) 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:

User Interface Component Contrast

visual identifiers (which cannot be achieved in another way that would conform) of user interface components have a contrast ratio of at least 4.5:1 against the immediate surrounding color(s), except for the following situations: ...

@steverep et al., I just completed the survey. One thing I commented upon is that in 2.0, “essential”only ever qualifies the barrier, not the content. Note that the definition for essential includes “the content” so the term cannot sensibly be used to qualify “content”.

One thing I commented upon is that in 2.0, “essential”only ever qualifies the barrier, not the content.

@bruce-usab, I completely agree. In other words, it is meant for an exception. This seems to be contradictory to your survey comment on UI Component Contrast though:

Here, essential is qualifying the identifiers. So why not keep it?

To answer in your words, because the identifiers are not the barriers.

@steverep, I missed the called where essential was discussed, and the minutes do not make clear where we ended up.

Yes, WCAG 2.0 currently only used the essential qualifier in exceptions. While it is clear to me that our definition requires that essential not be used to qualify content, I am pretty sure that it could be used outside of exceptions.

The WCAG 2.0 use of “essential” is only for full-stop-barriers-that-we-nevertheless-allow-in-exceptions. I think 2.1 might use “essential” in the context of partial-barriers-that-we-are-placing-limits-upon.

@bruce-usab, we had resolutions on all changes where it was just adding a link and a couple others. The rest were held up and I presume the chairs plan to circle back to them.

The issues cited are all addressed, so closing.