the /etc/hosts file in the Slackware installer image still has this in it:
# hosts This file describes a number of hostname-to-address
# mappings for the TCP/IP subsystem. It is mostly
# used at boot time, when no name servers are running.
# On small systems, this file can be used instead of a
# "named" name server. Just add the names, addresses
# and any aliases to this file...
#
# By the way, Arnt Gulbrandsen <agulbra@nvg.unit.no> says that 127.0.0.1
# should NEVER be named with the name of the machine. It causes problems
# for some (stupid) programs, irc and reputedly talk. :^)
#
# For loopbacking.
127.0.0.1 localhost
# This next entry is technically wrong, but good enough to get TCP/IP apps
# to quit complaining that they can't verify the hostname on a loopback-only
# Linux box.
127.0.0.1 slackware.example.net slackware
# End of hosts.
Brain-dead Red Hat does this when you install
127.0.0.1 hostname localhost.localdomain localhost
Eeagh! WRONG!