what means duplicate "config" entries in Kconfig file?

[Robert P. J. Day]

  [i just tried to email the Kconfig maintainer, but sendmail
suggested that that mail might not have gotten through, so i'll
toss this out here.]

  in my quest to clean up even more kernel config menus,
i ran across the following oddity in arch/i386/Kconfig:

-----

config MCA
	bool "MCA support"
	depends on !(X86_VISWS || X86_VOYAGER)
	help
	  MicroChannel Architecture is found in some IBM PS/2 machines and
	  laptops.  It is a bus system similar to PCI or ISA. See
	  <file:Documentation/mca.txt> (and especially the web page given
	  there) before attempting to build an MCA bus kernel.

config MCA
	depends on X86_VOYAGER
	default y if X86_VOYAGER

source "drivers/mca/Kconfig"

-----

  i'm not sure what it means to have two config entries with 
identical symbols.  can someone clarify this?  i'm just confused
(which should not come as a surprise at this point).

rday

p.s.  and i'm open to where i should be emailing those patches
if this list is not the right place.