In article <20171006133707.6406518C08E at mercury.lcs.mit.edu> you write: >Probably a good place to look is in the later 'Assigned Numbers' RFCs, and see >if they had any use prior to asssignment to this. A quick grep finds the first mention of 172.12 and 192.168 in RFC 1597. Nothing before that. R's, John