Rarian is a document cataloging system. The primary function of Rarian is to manage the information in OMF files for the help browser. When you install an application, the OMF file is copied to the /usr/share/omf/application-name directory.
Rarian contains a hierarchy of subject categories to which a help document can belong. The subject category of the document in the OMF file determines the location of the document in the table of contents presented by the help browser.
The hierarchy of subject categories is defined in the /usr/share/librarian/Templates/lang/scrollkeeper_cl.xml file. The subject category of a document must correspond to a category specified in this file. For more information about Rarian, see the documentation installed locally at /usr/share/librarian/. Also, see the community site at http://rarian.freedesktop.org/.