PDF files, part II: How does IE know?

[Rich.Harrington at co.hennepin.mn.us]

Hi, more on the wackiness of linking to PDF files.

   I told you all before how our machines with IE4 -- but only some of our
IE3.x machines -- were able to deal with a link to a PDF file even if the
target didn't have a .pdf extension (see <
http://supct.law.cornell.edu/supct/index.html >.  None of the PDF links
there have a .pdf extension).

   If you are running 95 or NT, right click on any of the links that say
"PDF version."  What do you see?  Does your browser know at this point the
document is a PDF document?  Some of our IE3.x machines don't know, and
they aren't able to correctly load Acrobat Reader and display the document.
Our IE4 machines don't know, but are able to load Acrobat Reader anyway,
and display the document once the link has been clicked.  Others of our
IE3.x machines somehow *do* know at that point, just by right-clicking on
the link, that the target is a PDF file, even though it does not have a
.pdf extension.  How do they know?  Is there an attribute in the HTML, or
is it linking to the document to check its properties?

   Perhaps you are thinking that I am fixating a little too much on this
little problem, and perhaps you are right.  But I do hope to gain some
understanding of how the browser works, so if any of you have some insight,
I'd sure be interested to hear it.

Thanks,
Rich Harrington
rich.harrington at co.hennepin.mn.us
Hennepin County Law Library
Minneapolis, MN