Set up a machine with a whole pile of disks, and make sure some of them don't have disk labels. Then do a kickstart install with the following fragment: autopart clearpart zerombr ignoredisk --only-use=sda,sdb,sdc,sdd,sde Note that you get warning dialogs for all the other disks, too. This shouldn't happen if --only-use was working.
Will be fixed in anaconda-12.27-1 by commit 5a03630a88b0.