Creation of negative claims

[rickj]

I believe we have overlooked an issue. The technique documents have final IF/THEN/ELSE statements to handle the absence of any claim by declaring a negative (e.g. "Appearance modifiability not known", "The publication does not include a conformance statement").

From a distributors perspective we are creating a 'claim' that the publisher never made.
From a consumers perspective we have placed a 'claim' into the record for that title, such that when searching a catalog for items with an accessibility claim, this 'created' claim will show up, yet it is not something the publisher created.

We need to put in some guidance that while we may recommend that the output of the technique calculations may result in the creation of a 'claim' that was not received from the publisher, users of the specification may want to (or need to, depending on their contractual obligation to publishers to only show what they received) choose to keep any claim for that key accessibility information category empty, rather than create a 'claim' statement that the publisher did not provide.

[rickj]

As discussed on the Nov. 21 call, this is a readability and clarity issue.

An example using the Navigation key area:

• The 3rd instruction at the ONIX techniques https://w3c.github.io/publ-a11y/a11y-meta-display-guide/2.0/draft/techniques/onix-metadata/#instructions-3 states: ELSE display "No information about navigation is available.". This is followed by a note saying: This key information can be hidden if metadata is missing.

• The 3rd instruction at the EPUB techniques https://w3c.github.io/publ-a11y/a11y-meta-display-guide/2.0/draft/techniques/epub-metadata/#instructions-3 states: ELSE either omit this key informtion if metadata is missing or display "No information about navigation is available."

1. Note the typo informtion/information in the EPUB techniques
2. I would recommend removing the note in the ONIX techniques (for each area) and putting it in the instruction (like the EPUB one does). For those implementors that focus on specific instructions this will avoid confusion about the creation of a negative claim
3. These statements do not appear for Visual adjustments, Supports nonvisual reading, and Conformance per the instructions at https://w3c.github.io/publ-a11y/a11y-meta-display-guide/2.0/draft/guidelines/#order-of-key-information, however, the statement there is ambiguous ("This is why these guidelines recommend that three pieces of key information should always be displayed"). The use of the words 'recommend', 'should', and 'always' do not give clear instructions. Can we use the W3C conventions of "MAY", "SHOULD", and "MUST" to clarify this. Perhaps "This is why these guidelines encourage that implementors SHOULD include these three pieces of key information, however, in the absence of any provided claims they MAY be excluded:"

[rickj]

The above change would also need to be made in the Guideline notes for 4.1, 4.2, and 4.3 where it currently says "This key information should always be displayed, even if there is no metadata (See the examples where the metadata is not known)."