You can list nicknames matching a value you have selected. You can list from 2 to 250 nicks.
Examples:
/msg nickserv list *jen*
/msg nickserv list *bot* 50
List is useful if you either need to find a particular nick or are looking for nicks that match a general pattern. For example, you can use list to search for nicks that might be attempting to impersonate administrative positions, but with searches broader than you would want to outright prohibit. However, whenever you start doing searches based on strings, you run the risk of people finding less obvious ways to use nicks that you would rather they not. Generally, actually monitoring the network is the best way to enforce rules, but this can be a tool to assist you.