I've just added erc-capab.el to the project. It contains a new
module, `erc-capab-identify', which adds support for dancer-ircd and
hyperion's CAPAB IDENTIFY-MSG - freenode.net uses this, for example.
With this enabled, you can mark unidentified users.
I've been using this functionality for a while in my personal
configuration, but I figured since we use irc.freenode.net as the
default server, I might as well clean it up, document it, and commit
it. I named the file erc-capab.el to leave room for any future
capabilities that might be added to the servers.