System.xml question

Where can i use these files for? i found like 8 system.xml files in the \c8\templates\ps and sub directories.

Who knows which system.xml i can modify to hide UI items for non administrators?

Thanks!

The most common changed system.xml files are system.xml in the ps and ps\portal directories

To hide all instances of a user interface element in IBM Cognos Connection, you must modify a system.xml file.

To hide user interface elements in Public Folders or My Folders, just modify the systm.xml file in the c8_location/templates/ps/portal directory.
To hide user interface elements in portal pages and dashboards with multiple tabs, modify the systm.xml file in the c8_location/templates/ps directory.

restart the cognos service after changing the system.xml. and if you have multiple dispatcher/content manager, change them all and restart the cognos services on these servers.

Another useful example:
http://www-01.ibm.com/support/docview.wss?uid=swg21504740