"Validate=" controls the level of security of your list, and not what
users are allowed or not allowed to do. With version 1.8a there is a
confirmation mechanism that does not require the use of passwords and it
allows users to execute commands that were previously not possible with
"Validate= All" because there was no way for a user to validate them. If
you want to restrict SIGNOFF and the like, you can use a list exit.
Eric