I think what you want to do is display the "Type" column. Try this:

- In the document library, go to "Modify Settings and Columns"
- Scroll down to the section called "Views" and select the view where
you want to add this column (e.g. All Documents).
- In the section called "Columns" you want to check the box that says,
"Type" (you may also want to change the order in which the columns will
appear)
- Click OK and go back to your document library.

Hope this helps!"

No, my problem is different: when I display the Type column the icon
that appear isn't a pdf  icon but a generic icon.
I knew how resolve this problem on SPP 2001 but not on SPP 2003.
Any idea?

Check out the following article on www.msd2d.com. It explains how to set up
search for pdf  (which Portal Server will not do out of the box) and how to apply
the pdf icon.

www.msd2d.com/.../Tip_viewitem_03.aspx

I always assumed that if the doc type wasnt an MS document-- .doc, .xls, etc-- that all you EVER got was a generic icon--- no????

No, you are able to associate an icon with each of the non-MS documents. The
article describes the xml file that you will need to modify so that the document
type is referencing an image file that you have included on the server.