This means the Results Page also displays the available Categories, so users can refine their search, using both Notes or Web.
If you're using a Category-based search originally, the Category list is the same, otherwise it's based on the Categories defined for your selected Databases (and even documents within each Database can be defined as different categories).
This functionality also applies to Domain Search and Frame/iFrame based searching.
For example, from a Web search like this;
You get results back like this (the 'Category' area, colours, fonts, logos etc are all customisable via CSS);
You can then click each category to search again using the same criteria, but limited to that category only, e.g. here searching only the 'File Systems' category;
and again in the 'Directories and Bulletin Boards' category;
The same functionality also applies to the Notes Client;
For more information or a demo version, please visit http://www.ionetsoftware.com/search.