If you try and enter a question mark as part of a password in a cisco router configuration you get a new line saying LINE as it thinks you want help for the current command.
The solution - send and escape (Ctrl + V) before the ? so it is not interpreted as a command.
Solution found here:
http://lanwanprofessional-tech.blogspot.com/2009/05/using-question-mark-for-secret-password.html
