With BukkitAffiliations, you are allowed to do /affiliations, which will give the player a list of server affiliations that your Bukkit server is friendly towards. An example of this is JoeShmoe does the command /affiliations, and in the chat, he will see this:
Server Affiliations for: {YOUR SERVER NAME} - {Server 1 IP} - {Server 2 IP}
And /help affiliations will say:
/affiliations - List the affiliations of the server.