Files to index in the folders listed in FoldersToIndex.

A file will be indexed if it matches one of the IncludeFilters and does not match any of the ExcludeFilters. Each string can contain one or more filename filters, separated by spaces, to apply to files in the directories selected. (ExcludeFilters can be blank.) If a filename filter contains a space, put it in quotation marks. A filename filter that does not contain a backslash is compared to the name of each file. A filename filter that contains a backslash is compared to the fully-qualified pathname of each file. 

Example:

Filename filters only apply to the FoldersToIndex. They have no effect on documents indexed using the DataSource API.