PDF "File Download" window?

Giganews Newsgroups
Subject: PDF "File Download" window?
Posted by:  AES/newspost (siegm…@stanford.edu)
Date: Sat, 18 Sep 2004

On many web sites or pages (including my own home page) clicking on
certain links will start downloading a PDF file, sometimes without the
author having provided any warning in the text of the page that this is
going to happen (although in some --  all? -- browsers the "next link"
line at the bottom of the browser window may show that the next line is
a ".pdf" file).

I was recently on a page in which clicking on a link brought up a small
"File Download" window which displayed som info on the PDF file and
allowed a choice of actually invoking the download or returning to the
original page.

Is there some special HTML capability I've not yet found that can be
used to implement this, with all coding right on a single main page?  Or
does it require setting up an additional page (i.e., file) to implement
this "File Download" capability?

And on the same subject:  Is there an HTML syntax that creates a link
that will just punch any browser's Back button? (so that no matter how
you get to a specific page, clicking this link will take you back to the
page you came from, as contrasted to using an anchor tag that points
back to a specific page)

Thanks for patience with novice queries.