How can I hide a directory from anonymous clients.

Use the HideUser or HideGroup directive in combination with the proper user/group ownership on the directive. For example, if you have the follow directory in your anonymous ftp directory tree: drwxrwxr-x 3 ftp staff 6144 Apr 21 16:40 private

You can use a directive such as "HideGroup staff" to hide the private directory from a directory listing. For example: <Anonymous ~ftp> ... <Directory Private> HideGroup staff </Directory> ... </Anonymous>