RIS, provide machine name during pre-installation

Using RIS, one can provide computername during logon.
This can be done using predefined settings, but when changing these settings when using Server and WS OS, this takes much time.
It can also be done by entering the system name during logon at boot from floppy or PXE.
Changes in the settings in some .osc and the .sif files have to be made.
I only have forgotten what settings need to be changed in these files to make the procedure happen as described.