On certain networks there are (+e) except and (+I (eye, not el)) invite lists.
The except list is so people that are included in a ban can still join. So if you ban an entire isp and an innocent user asks if he can join you could add him to the except list.
The invite list is so certain people can join even if the channel is (+i) invite only.
He wants to have an identifier to retrieve the addresses in these lists just like $ibl for the banlist.
