Reasons why pdf files are in Supplemental results

[roopa]

Hi,

I want to know all possible reasons of supplemental for pdf pages and also want to knoe the solution for that.

Please also tell me all possible reasons of google supplemental for html pages.

[tedster]

Below are links to some very thorough discussions on the topic. The "duplicate content" threads are included because, second only to to low PR for the url, having multiple addresses for the same content is a major reason for a file to be in the Supplemental Index. In fact, if the content of a pdf file is also contained in an HTML page (printable versions of pages, for example) then both are not likely to make it into the main index. It will often be (and should be, IMO) just one or the other.

Study of these threads will pay dividends:

Supplemental Results [webmasterworld.com] - what exactly are they?
Duplicate Content [webmasterworld.com] - get it right or perish
Duplicate Content [webmasterworld.com] - comments from Google's Adam Lasnik
Google PR [webmasterworld.com] - Page Rank FAQs

One reason for a non-duplicate pdf file to get a Supplemental tag could be low PR. How many links are likely to point to the average PDF file? It's not usually on a site-wide menu or even in the sub-section menu. So unless it offers some real powerhouse information, linked to directly by other sites around the web, a PDF file is often tagged Supplemental. If the pages that do link to the pdf gain in PR strength, then so does the pdf file.

By the way, the threads I linked to above are also linked from the Hot Topics [webmasterworld.com] area, which is always pinned to the top of the Google Search forum's index page.

[tedster]

You also requested solutions - and the obvious solutions are increasing PR and eliminating duplicate content. Also, be sure that the pages you want to see in Google's index would really be valuable to a person searching. That is Google's point of view, after all, rather than our viewpoint of "what would be valuable to this webmaster".

Some pages just don't belong in the results for frequently searched terms - see the "comments from Adam Lasnik" link above for his remarks. And for a very precise search, even a url with a Supplemental Result tag can still show up in the top ten.