Re: Use of "should" and "must" defined

On Tue, Apr 19, 2011 at 12:31 PM, <noreply@w3.org> wrote:

>
> Name: Glenda Sims
> Email: glenda.sims@deque.com
> Affiliation: Senior Accessibility Consultant at Deque
> Document: TD
> Item Number: G141
> Part of Item: Description
> Comment Type: editorial
> Summary of Issue: Use of "should" and "must" defined
> Comment (Including rationale for any proposed change):
> It might be useful to clearly indicate the definition of the words "should"
> and "must" for the purpose of requirements versus recommendations.  This
> would apply to all parts of WCAG 2.0.  I mentioning it here on this
> technique, because this is where I recently had a debate about what "should"
> means versus what "must" means.
>
> Proposed Change:
> Make it obvious that "should" is recommended while "must" is required.  You
> could use the definitions found at http://www.ietf.org/rfc/rfc2119.txt.
>  You could also consider making the words "must" and "should" hotlink to the
> definition.  Or, not.  Just an idea.
>
> ================================
Response from the Working Group
================================
We are adding the following discussion of the uses of "must" and "should" in
techniques to the introduction to the Techniques document. We hope that this
will clarify interpretations of the techniques. We are not using RFC 2119 in
our standard because it cannot be applied in a standard like ours with 3
levels of conformance.

"Some techniques use the word "must". Because this is not a normative
document, this word is not used in the sense of RFC 2119, as it is in WCAG
2.0. The colloquial use of the word "must" describes proper application of
the specific technique under consideration. It does not imply requirements
beyond the scope of the technique. This means it does not impose
requirements on interpretation of the Success Criterion to which the
technique relates."

Please let us know whether this still leaves misinterpretations in our uses
of these terms.

Loretta Guarino Reid, WCAG WG Co-Chair
Gregg Vanderheiden, WCAG WG Co-Chair
Michael Cooper, WCAG WG Staff Contact


On behalf of the WCAG Working Group