The basic idea of LaunchBar’s detailed configuration options is to get a well defined set of searchable items, and to exclude those items that you never want to search by name. This helps to increase the search performance and leads to much better search results, since the irrelevant, uninteresting items are never displayed.

Usually, people want to access the programs inside the Applications folder, but not all the Readme files or plugins that may be located in that folder as well. And the home Library folder usually doesn’t contain any interesting items at all. Therefore, limiting the indexing scope to specific folders and to specific types of items will help you to filter out the relevant ones.

For some folders (e.g. your Documents folder) it might, however, make sense to index every contained item.

Whether such a setting is useful or not depends on the number and the kind of items contained in that folder. For example, if you are a web designer, and your Documents folder contains hundreds of index.html files, you will find it quite annoying, that entering IN or INEX in order to access the iTunes - Next Song action will deliver hundreds of uninteresting index.html files, instead of other, more useful results. In that case it would make sense to index specific documents only instead of including the entire contents of the Documents folder.

Please note that LaunchBar is designed to manage about several thousand items. It’s therefore not recommended to index your entire hard disk (not even your entire home folder) including each and every file or folder.

If the LaunchBar index contains too many items, this will unnecessarily slow down your abbreviation searches, and the quality of the search result will suffer, since it will often be cluttered with items that you never want to see.

The configuration capabilities of LaunchBar will help you to keep the focus on the important, interesting items, and to ignore those that you never want to access via LaunchBar.

In addition to accessing items directly (by entering an abbreviation), you may also consider to use LaunchBar’s browsing capabilities. For example, you might configure LaunchBar to only search for Folders inside your Documents folder. Then you can access each folder directly (via abbreviation) and display the contained documents by pressing the space bar or the right arrow key.