Welcome new user! If you missed part of the new user sign-on process, here are a couple of helpful commands: NU Re-read the new user welcome message. ACB Auto call-back. Have the system call you back to verify yours phone number and provide you with more access privileges. (Usually, local callers only). In addition, use the HELP PROFILE command to learn about commands which may be used to change your user profile (Address, preferences, etc).