[dev-context] /AF key for attachments (in PDF/A-3)

Pablo Rodriguez oinos at gmx.es
Sun May 26 22:04:32 CEST 2019

```Hi Hans,

attachments in PDF/A-3 need to be related (as an array) to the document
with the /AF key.

I already reported this and I think that the most sensible value is to
relate them to the document.

That would mean to include the /AF key in the /Catalog dictionary.

I think this would be the easiest way to implement and to use it.