See the individual member documentations about special NAP options in use.
It will hide the index leaf from the NAP information unless we are in Autoindex mode. The leaves' titles are used as a description within NAP, and the toolbar will contain edit and delete links.
This will check against the configuration setting 'symlink_topic'. We don't do sanity checking here for performance reasons, it is done when accessing the topic, that should be enough.
This defaults to the current content topic unless overridden by the symlink topic feature.