Normal: Newly registered nicknames will require positive identification before access to the nickname is granted.
High: Enables the 'aggressive protection' mode for nicknames. When enabled, if you attempt to use a nickname that you do not have access to, services with immediately change your nickname to Guest.
Example:
/as services set autoprotect high
/as services set autoprotect off
The reason that we don't enable this by default is that new users that are not familiar with chat will register a nickname, disconnect and then when they reconnect they don't know the NICKSERV IDENTIFY command. So you might want to give some thought to how your user base will deal with this being enabled. An Enterprise Edition only feature.