HN automatically adds Scribd links to PDF links (because Scribd was part of YC S06).

The scribd link appears anytime you submit a PDF directly. This was/is useful for people who hate downloading PDFs, since scribd does not require this. Of course, a lot of us (myself included) use Chrome, which allows you to open PDFs inline...

From what I remember, the scribd side is even flakier than opening a PDF in your browser. And I'm not too keen on this "push our dogfood on readers" policy, either...

You may also view PDFs within the Firefox browser with the Acrobat or Foxit plug-ins.