Annotations are not working in other PDF readers.

There seems to have been a bug open for this before.

https://bugs.kde.org/show_bug.cgi?id=353400

And changed to 'invalid' .  I strongly disagree with the resolution in this bug.

Here are the steps to reproduce:

1. start with a fresh PDF
2. add annotations (highlights, notes, etc).
3. save the PDF
4. re-open the PDF in Okular to show that they are still present.
5. open the PDF in various other readers.  About half of them fail. 

The important ones seem to fail too. Note that they work with all the other apps. I can use Preview (the mac OS PDF viewer), Adobe Acrobat, PDF.js, Foxit Reader, etc all interchangeably and the annotations work.  


Okular is the one that exhibits this behavior consistently.


Here's Okular showing three annotations:


https://imgur.com/q4BuC68


(sorry it's a little small)


Here is Foxit Reader (only two shown):


https://imgur.com/KgdTIOF


Here is the output from PDF.js (no annotations visible)

https://imgur.com/o3i5D1C


If you don't have 3rd party PDF software installed you can easily use PDF.js to verify:


https://mozilla.github.io/pdf.js/web/viewer.html


I think the argument here is that 'appearance streams' in PDF are optional as part of the spec.

However, what's happening is that this is the dejure vs defacto specs.

The annotations are pointless if the user can't see them.

One of these, the 'note' annotations, is completely invisible. I can't see it so I can't click on it to read the note.  

I agree with you that by dejure standards the appearance streams are optional.  However, by defacto standards they are *not* because all other PDF editors are using appearance streams.  

Invisible appearance streams might be good for machine readable annotations but not for humans.  I have no idea where on the page to click for my annotations.