Registers your nickname with NickServ. After registering your nickname you will always be able to use it. Other people can use it without getting access to your ops or memos unless you set protect on. When registering a nick, an entry is added to your nick access list. If your user@host mark is david@203.245.259.22, then *david@203.245.259.* is automatically added to your access list. In general, the automatic access list entry will be useful, but you might want to consider customizing your access list. Nicks will expire if not used regularly, the exact expiry time is set by the chat network. Roots can set nicks to not expire, see held under root commands for more information.
Example:
/msg nickserv register MypassworD jim@webmaster.com
Registering a nick is an important part of using a chat network. Your nick is your identity, the only way that people will be able to recognize you. Nicks also allow you to receive memos, get status in rooms, and register your own rooms (although depending on the way the network is set up, you may need to be a network operator to register a room). It is best to have one primary nick that people know you by, and sometimes one or two extras for various purposes. You should not register a large number of nicknames, as it is pointless and wastes database space.