[dgudkov]

The PDF format supports attachments (embedded files). I'm thinking about a set of libraries and/or a command-line utility that would make it trivially easy to attach a SQLite|JSON file to a PDF or extract one from a PDF. This won't fix existing files, of course, but at least for those apps that generate PDFs it will be easier to embed a SQLite/JSON into a generated PDF.

[oever]

XMP is meant for adding semantic information to (parts of) PDF files.

https://en.wikipedia.org/wiki/Extensible_Metadata_Platform