kernel-image-2.4.18-686 vs. kernel-image-2.4.18-1-686

["Sven Heinicke" <sven@nec-labs.com>]

$ apt-cache search kernel-image 2.4.18 686
kernel-image-2.4.18-686 - Linux kernel image 2.4.18 on PPro/Celeron/PII/PIII/PIV.
kernel-image-2.4.18-686-smp - Linux kernel image 2.4.18 on PPro/Celeron/PII/PIII/PIV SMP.
kernel-image-2.4.18-1-686 - Linux kernel image 2.4.18 on PPro/Celeron/PII/PIII/PIV.
kernel-image-2.4.18-1-686-smp - Linux kernel image 2.4.18 on PPro/Celeron/PII/PIII/PIV SMP.

What's the difference between 2.4.18 and 2.4.18-1, and why is there no
security upgrades for kernel-image-2.4.18-686.  Is it not vulnerable?

	Sven

p.s. I have the itchy feeling this is a stupid question, but I've been
wondering for a while.  Now with the new security upgrades I thought
to double check.