I see you havent had a reply yet, so heres my two pence worth.
Are you talking about MCs document management ability, or music/image files? I know nothing about the former, although I dont think it makes any difference in this case (MC will catalogue your PDFs, but not create any).
AFAIK you cannot export an HTML playlist, or any other library element, to a PDF in MC without some external program to actually create the PDF file. At least File/Export playlist in MC11.0.309 gives no PDF option.
Perhaps you exported the playlist into HTML, opened it in another program and then further created the PDF? I know (for example) that Openoffice will do this, but Im sure there are many others.
Alternately, if you added some sort of external PDF creator program through Tools/Send To/Send to (external)/Add edit programs its possible you could have 'sent' a playlist to a PDF directly through that third program within MC (I guess).
Sorry, no clear answer. Hope it helps though.