RE: Question about Metadata

> My question then is: if we are no longer referencing idpf.org <http://idpf.org> , then should the entry "prefix="a11y: http://www.idpf.org/epub/vocab/package/a11y/# <http://www.idpf.org/epub/vocab/package/a11y/> " " be removed or modified?

 

If you use any of the a11y:* properties in your metadata, then it’s better to keep the prefix declaration. The a11y prefix is technically one of the “reserved prefixes <https://www.w3.org/TR/epub-33/#sec-reserved-prefixes> ” per the specification, but refer to the caution box at the top of the section I’ve linked to for why you shouldn’t rely on reading systems or vendors accepting  them undeclared (it goes back to EPUB metadata’s not-fully-implemented RDFa roots).

 

> The current Best Practice seems to be in conflict with current guidance to remove idpf.org <http://idpf.org>  references...

 

We’ve tried to remove IDPF references from the specifications, but these are namespaces. We couldn’t change the namespaces without invaliding all existing EPUB content, so the ones that existed prior to EPUB 3.3 had to be retained.

 

> <package version="3.0" ...  Actually, I am unclear whether this metadata declaration should remain (modified to version 3.1)

 

Retaining the version number at 3.0 was a core piece of the charter. It’s a major interop problem for some reading systems if the version changes, as they aren’t required to open publications with a version higher than 3.0. We tried bumping the version to 3.1 with the (largely forgotten and unimplemented) 3.1 revision, but had to walk it back with 3.2. In other words, just keep it at 3.0.

 

The best way of thinking of it is that there are EPUB 3 publications, as defined by version=”3.0” in the package document. The 3.X standard numbers don’t change that, only modify what a valid EPUB 3 file is. 

 

> and that metadata entry also specifies "xml:lang="en" " - what to do with that?

 

The language declaration on the package element sets the language for all the metadata in the package document, so I wouldn’t see any reason to remove it.

 

> IF the <package> declaration remains (??), I do understand (I think) to remove the namespacing of "xmlns="http://www.idpf.org/2007/opf" xmlns:m="http://www.w3.org/1998/Math/MathML"" (right?)

 

No, only the mathml prefix declaration can be removed. If you take the default namespace declaration off the root package element, then the markup wouldn’t be recognized by an XML parser as being a package document (back to why we can’t remove the existing IDPF namespaces).

 

Hope that helps.

 

Matt

 

From: John Foliot <john@foliot.ca> 
Sent: Friday, June 9, 2023 12:00 PM
To: Matt Garrish <matt.garrish@gmail.com>
Cc: John Foliot <john@foliot.ca>; W3C EPUB 3 Working Group <public-epub-wg@w3.org>
Subject: Re: Question about Metadata

 

Hi Matt,

 

No, the entries were pasted in. The first one was this:

<package version="3.0" unique-identifier="pub-id" prefix="a11y: http://www.idpf.org/epub/vocab/package/a11y/# <http://www.idpf.org/epub/vocab/package/a11y/> " xml:lang="en" xmlns="http://www.idpf.org/2007/opf" xmlns:m="http://www.w3.org/1998/Math/MathML">

 

From the FAQ at http://kb.daisy.org/publishing/docs/metadata/evaluation.html :

* Does the a11y: prefix have to be declared in the EPUB package document?
Technically, no, but best practice is to always declare the prefix.

(My question then is: if we are no longer referencing idpf.org <http://idpf.org> , then should the entry "prefix="a11y: http://www.idpf.org/epub/vocab/package/a11y/# <http://www.idpf.org/epub/vocab/package/a11y/> " " be removed or modified? The current Best Practice seems to be in conflict with current guidance to remove idpf.org <http://idpf.org>  references...)

Re:  <package version="3.0" ...  Actually, I am unclear whether this metadata declaration should remain (modified to version 3.1) or be removed - and that metadata entry also specifies "xml:lang="en" " - what to do with that?

 

IF the <package> declaration remains (??), I do understand (I think) to remove the namespacing of "xmlns="http://www.idpf.org/2007/opf" xmlns:m="http://www.w3.org/1998/Math/MathML"" (right?)
______________

 

The second entry was:

<metadata xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:opf="http://www.idpf.org/2007/opf">

The question there is, do I leave the purl.org <http://purl.org>  namespace declaration and just remove the idpf.org <http://idpf.org>  reference, or should that entire declaration be removed from existing legacy books as we modify/update them going forward?

Thanks!

 

JF

 

On Fri, Jun 9, 2023 at 11:16 AM Matt Garrish <matt.garrish@gmail.com <mailto:matt.garrish@gmail.com> > wrote:

Hi John,

 

Did you miss pasting the metadata entries? All I see in your message are the package and metadata element declarations.

 

There are two pointless namespace declarations on them, though, if that’s what you’re asking. Specifically:

 

> xmlns:m="http://www.w3.org/1998/Math/MathML"

 

MathML elements aren’t valid in the package document (including in EPUB 2), so declaring a prefix does nothing.

 

This namespace declaration on the metadata element is also pointless in EPUB 3:

 

> xmlns:opf="http://www.idpf.org/2007/opf"

 

EPUB 2 had opf:* prefixed attributes but they were all removed in EPUB 3 and replaced by the refines mechanism.

 

Matt

 

From: John Foliot <john@foliot.ca <mailto:john@foliot.ca> > 
Sent: Friday, June 9, 2023 9:50 AM
To: W3C EPUB 3 Working Group <public-epub-wg@w3.org <mailto:public-epub-wg@w3.org> >
Subject: Question about Metadata

 

Hi All,

 

Seeking some clarification here. We have a large quantity of legacy books we are in the process of reviewing and updating. These books have older ePub 2 metadata declarations, and specifically the following 2 entries:

<package version="3.0" unique-identifier="pub-id" prefix="a11y: http://www.idpf.org/epub/vocab/package/a11y/# <http://www.idpf.org/epub/vocab/package/a11y/> " xml:lang="en" xmlns="http://www.idpf.org/2007/opf" xmlns:m="http://www.w3.org/1998/Math/MathML">

<metadata xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:opf="http://www.idpf.org/2007/opf">

 

My question is, do I just remove these 2 entries, or are they supposed to be replaced with something else? I've looked over the current documentation and it's not explicitly clear what to do here (or, at least I cannot determine what to do). The Daisy Knowledge Base seems to suggest they can just be removed (http://kb.daisy.org/publishing/docs/metadata/evaluation.html), but I cannot confirm that for sure.


Thanks for any feedback/guidance provided.

 

JF
-- 

John Foliot | 

Senior Industry Specialist, Digital Accessibility | 
W3C Accessibility Standards Contributor |

"I made this so long because I did not have time to make it shorter." - Pascal "links go places, buttons do things"




 

-- 

John Foliot | 
Senior Industry Specialist, Digital Accessibility | 
W3C Accessibility Standards Contributor |

"I made this so long because I did not have time to make it shorter." - Pascal "links go places, buttons do things"