This is a new category that I want to blog about. I have had some agonies over whether to show files that are not in the OPF. Liza Daly clarified this with her Bookworm ePub check recommendations that make a lot of sense in terms of compliance vs. reader behaviour.
- Case 1, where the file is declared in the OPF but is not in the package. Display what can be displayed. Issue a warning - There are files in the OPF that are missing in this ePub package.
- Case 2, where the file is in the package but is missing from the OPF. Display what can be displayed if anything but do not display/use files that are not in the OPF. Issue a warning - This package appears to be incomplete. It contains files that are not listed in the OPF.
We will wait to see if we will give a list of files at this stage.
Because ePub is a collection of Internet technologies, a lot of files can be referred to from the XHTML and could display where a reader is based on technologies like WebKit (which AZARDI is). However there are some which are not always so easy to handle such as fonts, SVG, XML Islands and objects.
