This category allows you to configure the full-text indexing feature of Chamilo. It requires, however, the php5-xapian module (as well as a few additional applications) to be installed on the server in order to work. This feature was previously available only in the medical version, but was added to mainstream Chamilo 188.8.131.52 as is the engagement from the Chamilo official providers.
You will need to enable this feature and define an additional search tag (ie “Author”) before you upload documents in order for these to be indexed (and searchable).
Don't hesitate to ask for dedicated hosting from one of the Chamilo's official providers if you've got issues setting it all up.