PDF blog post content problems: 2024-08-20-pdf-attachments

[ronaldtse]

From @petervwyatt:

• It would be good to list a few other options for free reader apps besides just Adobe - Foxit, Apryse, Xodo, and Xpdf all support attachments. I would go so far as to say that the vast majority of standalone PDF viewers support attachments. It's mainly the browsers that are hamstrung.

• Firefox (pdf.js) DOES support attachments but you need to scroll the PDF page into view first for file attachment annotations (see this bug I raised: Not all file attachments are shown on initial opening, but appear later mozilla/pdf.js#17821 - the updated URL for the test PDF mentioned in this issue is now https://labs.pdfa.org/FragmentTest.pdf if you wish to confirm). But associated files with AFRelationship (i.e. those in the EmbeddedFiles name tree) will appear from the start.

• under "Considerations of delivering attachments in PDF" I would also suggest a "Security" bullet stating that due to viewer security concerns, some types of embedded files (e.g. anything executable - exe, scripts, etc.) may not be extractable from PDFs even if embedded, so do not attempt distribute in this manner.

• the Usage section is outdated (cf. https://www.metanorma.org/author/topics/sections/attachments/) - this was why I didn't previously note more recent changes support the description