Exclude pdf files?
Is there an easy way to exclude all pdf files from being indeed and from search results? I have links available to many pdf files on each relevant page. How do I stop Yahoo following those links and indexing them?
The situation is that I have a site with many long and fairly academic abstracts and essays. For convenient off-line reading, I provide pdf files of many of them. The content is identical. But since both the pdf and the ordinary pages are being indexed over at Yahoo, all searches are returning results twice over. Since half the searches returned are redundant, because they are repetitions, I would like to get rid of them.
Putting the pdf files in their own separate directory doesn't seem to help.
Thanks very much indeed for any help.