USB booting :: Unnecessary syslinux/usb files?

I get a bit neurotic about having unneeded files cluttering up the directory listing, and was wondering which of the files can be erased?

boot.cat
boot.msg
f2
f3
german.kbd
knoppix/
ldlinux.sys
linux24
logo.16
minirt24.gz
readme.txt
syslinux.cfg

Of course, linux24, minirt24.gz, KNOPPIX/KNOPPIX, and syslinux.cfg are needed, but are boot.cat, boot.msg, logo.16, f2, f3 and german.kbd needed at all?

yes, they are needed, only readme.txt can be deleted..
boot.cat is only effective on cd's, so if you have a frugal install it could be removed though.

To complement my prev answer, f{2,3} and the picture are technically not needed, but nice to have to be able to look at cheat codes and to have a DSL logo there.

original here.