Changing pdf security

I have written about this issue before (here), but I encountered a new variant on this problem recently, when I had a pdf file which apparently had no security, but would still not let me add a comments bubble to it.

When I found I could not append a comments bubble, I tried adding a text box, but this facility was also denied. I was also unable to simply write directly on the file.

Not being able to write on the file poses a problem. You see, when I get academic articles, I always add a comments bubble on the front (a 'sticky note') in which I put the APA reference and DOI. This is so I always have the full reference to hand right on the item, and so that - should I want to share the item with anyone - they too have the reference. The item can be tracked back to its source... which is, after all, the reason for references.

So I went hunting for what to do. I found a lot of ideas, but none of them worked. Instead I had a good trawl around in Adobe Acrobat itself, and hit paydirt on the security tab under File | Document Properties.

The "Commenting" function has a "Not allowed" entry beside it, marked with an asterisk, followed by an asterisked note at the bottom of the page, as follows:

"* This document restricts some Adobe Acrobat features to allow for extended features in Adobe Acrobat Reader. To create a copy of the document that is not restricted (and has no extended features in Adobe Acrobat Reader), choose File > Save a Copy

Ah. I tried this: and it worked perfectly.

I then considered just how rare it is that software contains within itself the actual, clear answer. That is, providing we know where to look.

Sam