Secure upload facilities

The following snippet from a sample configuration file illustrates how to protect an "upload" directory in such a fashion (which is a very good idea if you don't want people using your site for "warez"):

<Anonymous /home/ftp>
  # All files uploaded are set to username.usergroup ownership
  User username
  Group usergroup
  UserAlias ftp username
  AuthAliasOnly on
  RequireValidShell off

  <Directory pub/incoming/>
     <Limit STOR CWD XCWD>
        AllowAll
     </Limit>
     <Limit READ DELE MKD RMD XMKD XRMD>
        DenyAll
     </Limit>
  </Directory>
</Anonymous>

This denies all write operations to the anonymous root directory and sub-directories, except "incoming/" where the permissions are reversed and the client can store but not read. If you used <Limit WRITE> instead of <Limit STOR> on <Directory incoming>, ftp clients would be allowed to perform all write operations to the sub-dir, including deleting, renaming and creating directories.