Re: requirement 8

Gregg wrote:
> You just don’t want overlap on the same level — or a requirement at a lower level that is already covered by a higher level.

So if 1.4.8 (requiring 200% without horizontal scrolling) were still at AAA, it would conflict with the new Resize content’s 400% without horizontal scrolling at AA [1]. It would still conflict if 1.48 were moved up to AA.

I think the logical outcome is that any SC which increases a requirement will create overlap/conflict, therefore we will have to edit current SCs.

I suggest that we add an ‘impact assessment’ for each SC description to explicitly outlines the possible impact on other SCs, and review the techniques/failures of the impacted SCs.

I don’t think it has to be that big a thing in most cases, for example the new Resize content [1] would impact the 1.4.4 & 1.48 techniques, which already overlap. It would be a case of re-assigning, de-assigning, or moving from sufficient to advisory current techniques that apply to those two SCs, and perhaps adding new techniques for the new SC.

That is already underway on Resize content [1] under ‘Techniques’, but I don’t think we have thought through where techniques/failures might be retired from 2.1 if a current SC is modified.

A wider review could point out more overlaps/conflict, and the impact assessment would be a good place to record that.

Cheers,

-Alastair

[1] https://github.com/w3c/wcag21/issues/77