On Friday, January 23 2009, Alan Pevec said:
so it should be removed from sys/extlinux.cfg to avoid error
message:
unknown keyword in syslinux.cfg
It is masked by the menu, shows up only with custom image builds where
isolinux.cfg is modified.
See
http://syslinux.zytor.com/wiki/index.php/SYSLINUX#LOCALBOOT_type_.5BISOLI...
It's actually supported with 3.70+ which is queued up to go into rawhide
after the alpha goes out.
Jeremy