itextSharp - Merging pdf files disables extended reader permissions

Question

I\'m using Itextsharp v5.1 and created enabled reader pdf files. I wrote a c# class that fill the form and keep each individual pdf file extended reader. But, when I use this Me

Answer 1

In order to preserve existing reader enabled permissions, you have to use a PdfStamper in APPEND mode.

There are also a number of things you Shouldn't Do to such a PDF or you'll disable the extra permissions anyway... I believe "add pages" and "add annotations/fields" are on the list of things you can't do.