Each of these links is assessed in several ways by the search engine; does it work? linked text, target page title, target page meta, target page content. All of these are then compared to the originating page and its own title, meta, content.
Search Engines dislike duplicate content. Pages with identical page title and meta descriptions are considered identical content to Google and these pages will be relegated to the supplemental index. The supplemental index is the second string database by google - which is ranked lower than the main database.
Joomla PDF is a nice feature which enables you to view your content items in a PDF format.
The down side to enabling this function is that the PDF version of the content item could be recognized by the search engines as a duplicate of the original published content item and you could get penalized for this.
To avoid getting penalized for generating duplicate content do the following.
- From the Administrator area select the Global Configuration option
- Now select the content tab
- Next to the PDF Icon select the Hide radio button
- Save your settings
- The PDF icon will no longer appear in your content items
This is the good start but it is not complete because there could be other reasons for your pages being stuck in the supplemental index.
