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Comment by chmod775 | Hacker News Reader

Sometimes I feel we're never going to be rid of PDFs. Everything can be converted into one, but you can't reliably convert from it.

They're going to be here in 200 years.

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They have become a reliable way in office & legal processes around the world in terms of fixed layouts & content immutability (in a sort of layman view. Knowing Acrobat Pro exists & PDF editing too - but I'd argue that in majority of cases its not as trivial as modifying text file or markup sources, with intention to change or forge).

Correct me if wrong but Word/LibreOffice layouts could change depending on the machine & version number - but with PDF you get what you intended to show. I think that has always been the winning proposition for PDF

https://en.m.wikipedia.org/wiki/PDF/A

PDF/A is made especially for archival and long term preservation

It's just a useless label on the cover. PDF/A is nothing but a subset of PDF without proprietary expandability limited to what is considered to “work everywhere” when dealing with common printed matter. It adds nothing to non-existent error handling rules or parsing strategies. There are 5 different ways for an object to be found undefined/nil, but the specification is silent on whether there's any difference in meaning or handling based on the level it happens. Therefore libraries and tools do what they find most suitable, and anything generated by the numerous easy-to-use sites is potentially not quite the same as originally uploaded.

PDF resembles the state of HTML years after HTML4, it barely says what should happen in the best case.

Word offers content immutability with its read-only mode, not sure how much layout change there is, though how much pixel perfection do you need in legal processes that are mostly pure text?

Ever observed how legal documents, product documentation, books etc., are typeset - with exact placement of comment boxes, US code reference/legal disclaimers/ barcode, precise footnotes or margin notes. Many of those are meant to be also machine readable when printed out. Exactness is a very pressing need.

I would recommend taking a good look again. It might answer you why it is preferred in some situation to be typeset in PDF over a format where text could reflow.

About the immutability in Word, it seems optional & not something by design. You can edit any *docx & 'Save it as' back. This feature doesn't absolve immutability as a principal feature.

If you have a 300-page legal document, and other sources reference passages, e.g., a paragraph on page 234. It would be unreliable if over the years or depending on the viewer it moves to another page.

that's why legal documents number the paragraphs, otherwise it's unreliable over the days you edit the document, no need to wait years for the app to change layout

Isn't the solution to that not to fix your document’s pixels, but rather to have auto updating references (a la LaTeX)?

What version of word. PDF has many free implementations for both reading and writing.

Does read-only mode not suffer from some global settings? Also, what happens when the reading instance doesn't have all the used fonts for example?

What global setting?

Nothing happens, embedded fonts feature isn't exclusive to PDFs

Sometimes vital images disappear and the layout gets messed up. I haven't had that happen to me with a pdf.

Though keep in mind that a given PDF might not embed the font that it uses (the PDF creator might not even have the legal right to embed whatever font they're using), so opening a PDF on other machines can cause them to be messed up if those machines don't have the correct fonts installed.

If you want literally pixel-perfect layout, you need to use a raster image format like PNG.

PDF is a container. You can put TIFF images, one per page, into the file

I look at PDF like a virtual sheet of paper. Once you "print" to it, abandon any hope of getting things back out.

This sounds like a bad thing, but we need some kind of way to say "this is the final presentation no matter what".

The conversion tools in Acrobat recover most content pretty well. It's not a one to one conversion, but it is plenty usable for putting in new documents or whatever.

Which is bothersome when you disagree about not needing to extract data or modify.

PDF probably some some feature that let's you embed machine-readable data (or the original file in its entirety)

Reminds me of how Adobe Illustrator files were also pdf files and you could view them as PDFs when you rename the extension to .pdf. (this might also apply to Photoshop .psd files)

I feel that there's a lot of value in how a finished PDF document is visually inflexible. This is how the document looks, and this will be how the document look in the next generation PDF viewer on a completely different computing platform of a different type of device. If it works on my machine, it works on yours, too. (This is ignoring the dynamic PDFs with javascripts in them)

It doesn't evolve with the electronic device, which means you might need to zoom and pan, but it also means that it probably won't be completely bungled.

I've bought an EPUB which only works on iPad. If the screen is sized differently, or uses a different font, etc., the texts are all messed up. It simply wouldn't happen if the book was distributed via PDF.

> Everything can be converted into one, but you can't reliably convert from it.

My favorite “workaround” for turning a pdf into html is to render the pdf with something like pdf.js; create a canvas, render contents, scale responsively, done. It works good enough for e.g. displaying book previews. Demo: https://merely.xyz/seven-photo-challenges/ (photo exercise ebook).

indeed, such a sad state of affairs when one of the most popular digital document formats isn't really a proper digital document, but a hack to resemble the bad old paper days

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