I posted a comment to Mark Jordan's "Self-Education of Systems Librians" concerning the fact that Mark linked to a PDF. I asserted that linking to a PDF is like posting html to a news group, not the best of form. Dan welcomed me to the group by claiming that my comment was not helpful. I apologize if I offended. H suggested I post an opinion, so here it is.
In that post I made a reference to a Jakob Nielson article PDF: Unfit for Human Consumption I don't know if Dan read that article but I think Nielson's point is a good one, that PDFs are not good for use on-line.
I may be more sensitive to this issue than others for in my current situation I find more and more poeple want to upload and link to Word, PowerPoint, and PDFs when there is nothing about the those documents that that can't be expressed in html. In my situation these formats cause much more trouble than they're worth. I am encouraging all the people I work with to think hard about the format of their docouments and to try and ensure that those documents don't lock the message and intent in hard to use document formats. I am also encouraging them to encourage others to create better documents. It is also a challenge for me because I have to create systems that either convert all those formats to something usable or create systems that allow them to create better documents in the begining.
Dan made the point that PDFs are "good enough" and that maybe true. My point was that they are not what I (IMHO) would consider "best practice".
Again I apologize if my criticism offended. I just think usability counts.