DALnet's nick registration service allows users to register a nickname by providing a password, preventing other users from using it. NickServ registration is required for such things as registering channels and sending/receiving memos.
After registering a nickname with NickServ, you will gain access to ChanServ, which allows you to register channels, as well as receive AOP or SOP status on channels.
To disallow users from granting you AOP/SOP status, use this command.
Command: /nickserv set NOOP (on/off)
Example: /nickserv set noop on
/nickserv set noop off