The ban and topic info currently only hold the nick as the one that set it (or a * in case a server set it, if i remember correctly). A nick doesnt mean that much, it could have been anyone, the account info would be much more meaningful to have there. For example, the topic is set by nick (when the user did not have an account), or set by (for example) account.users.undernet.org. It doesnt seem very useful to also save nick and username. Saving account instead of nick shouldnt use much more memory (nicklen is 12, accountlen is 12). This format shouldnt break clients, as in previous ircu version servernames could appear there, and other ircds can show the full nick!user@host there. While this does add a bit more traffic when showing the banlist to clients, for topics this adds only very little i think. Perhaps for channel services always show nick, as showing X.users.undernet.org doesnt seem very useful.