arp self reference

Hi,
	for references purposes, I tried to find in the RFCs without success a 
reference describing the arp self mechanism, which is used by many 
implementations in IPv4 to verify the usability of an address. Anyone can 
help me find the reference?
        thanks in advance.
Marc.

PS. just for the fun of it. here is an extract of the arp rfc (RFC826): 
"The Problem: The world is a jungle in general, and the networking game
contributes many animals." looks like it is still true! ;-)))