Re: EPUB 3.3 spec conformity issues

[Patrice Dumas]

On Tue, Aug 20, 2024 at 09:23:57AM +0100, Daniel Cerqueira wrote:
>
> The dcterms:modified meta element is MANDATORY in order to create a
> valid EPUB 3.3 file. It is missing in the current Texinfo EPUB file
> creation. Here is an code example on how to implement this inside the
> EPUB file:
> 
> According to: https://www.w3.org/TR/epub-33/#sec-metadata-last-modified

I agree on the issue, but I do not think that the last modified date
should be the date of the epub file generation, it should rather be the
date of the publication contents or style modification.  None of the
Dublin core nor the EPUB format specification are clear on what the
modification date should correspond to in term of changes, but my
reading of the EPUB specification is that it is about the published
material, not about the epub file creation date.  I also think that it
is much better to have this date correspond to the change in contents
not to the generation.

To me this should be specified by the manual authors.  One possibility
could be to use the last modification time of the input Texinfo file,
possibly through automake setting the UPDATED flag, but this should be a
user's choice, not something automatic.

Adding metadata such as a last modified date to Texinfo is on the TODO
list since some time now, but I think that we are too near from the
release to change the Texinfo language now, this cannot change before
the release.

> I consider this to be a bug, because the EPUB file created by `texi2any`
> is not according to the specs.

We do not try to follow standards for the sake of it, but if there are
actual issues.  Here it would be better to be conforming, as the
modification date is used in readers, but it is not such a big issue
either, as it does not prevent the readers to render the epub files.

> A suggestion when programming this, is to always use the `epubcheck`
> program to validate the creation of EPUB (by texi2any), from now
> onwards.

There were already some reports on epub files validity when the epub
output was implemented and I do use epubcheck to find non conformance
(though not recently). But it does not means that the issue can be nor
should be fixed.

I will answer the border issue in another mail.

-- 
Pat