Question: The PDF viewer Okular (part of KDE desktop) has lots of nice features and supports lots of file formats.
One of the things I like about it is the comments and annotations.
Unfortunately, all of the comments and metadata (like last viewed page) get stored locally in:
**~/.kde/share/apps/okular/docdata**

Is there any way to make Okular store them in the PDF itself?

Answer: 
After making any annotation using Okular, 

Go the the Print option (in File Menu or Ctrl+P) and then in the **Name** option change the value to Print to File(PDF) and in the **Output file** option give the path of the output file you need. 

Voila, your annotations are now a part of your new PDF.
> 
> From okular faq:
> 
> 
> **How can I annotate a document and send it to a friend/colleague/etc?**
> 
> 
> Since KDE 4.2, Okular has the "document archiving" feature. This is an Okular-specific format for carrying the document plus various metadata related to it (currently only annotations).
> You can save a "document archive" from the open document by choosing "File -> Export As -> Document Archive".
> To open an Okular document archive, just open it with Okular as it would be eg a PDF document.
> 
> 
> 

<http://forum.kde.org/viewtopic.php?f=20&t=107182#p247428>