Hi Alan, Can you clarify what you are trying to say with "but at the beginning it still allows me"? Also, I am not clear about your syntax. The dollar sign is not a valid parameter to those commands, so it looks like you are trying to use a regular expression. But you have not checked the Regexp boxes. Without those checked, the strings will be interpreted literally, i.e. we will only block "who -a$", not "who -a". To block the latter you have to drop the dollar sign, or check the Regexp box. If you use it as a regex with dollar sign, we will block "who -a", but not "who -al". A regular expression "who -.*" would block the who command with any parameter added.