%BNickServ SIDENTIFY%B is similar to the IDENTIFY command. The
difference is SIDENITFY changes your nickname while
identifying.
It will automatically release an enforced nick, but it will
not ghost or recover your nick if another user is using it.

Syntax: SIDENTIFY <nick> <password>

Example:
/msg nickserv sidentify yournick yourpass
This command is mostly useful if you use HIGH protection on your nickname.
	  