CentOS - Apr 2008 - Adding Ethernet alias (why 3 hard links for an ifcfg-eth file?)

I need to add eth0:1 with a new IP address to my C5-based router.

Does a design document exist for the ifcfg family of scripts that explains 
how they're to be used? Before I go digging through the script hierarchy 
I'm hoping someone can point me to documentation to make the process easier.

One confusing issue is that the ifcfg-eth* files in 
/etc/sysconfig/network-scripts are hard-linked to same-named scripts in 
sibling directories:

85327883    8 -rw-r--r--   3 233 Apr 11 12:34 
./networking/devices/ifcfg-eth1
85327884    8 -rw-r--r--   3 210 Apr 11 12:34 
./networking/devices/ifcfg-eth0
85327883    8 -rw-r--r--   3 233 Apr 11 12:34 
./networking/profiles/default/ifcfg-eth1
85327884    8 -rw-r--r--   3 210 Apr 11 12:34 
./networking/profiles/default/ifcfg-eth0
85332182    8 -rw-r--r--   1 254 Jun 20  2001 ./network-scripts/ifcfg-lo
85327883    8 -rw-r--r--   3 233 Apr 11 12:34 ./network-scripts/ifcfg-eth1
85327884    8 -rw-r--r--   3 210 Apr 11 12:34 ./network-scripts/ifcfg-eth0

(I excised the ownerships to make these fit on a line. First column is the 
inode number.)

I'm not using a GUI, and I figure the easiest way to add an alias is by 
hand-editing a new config file, but I'd like to know what these hard links 
are for. Which scripts reference the 3 different paths?