A user name and password may be supplied; they are used in the ftp "USER" and "PASS" commands after first making the connection to the FTP server. If no user name or password is supplied and one is requested by the FTP server, the conventions for "anonymous" FTP are to be used, as follows:
The password is supplied as the Internet e-mail address of the end user accessing the resource.
If the URL supplies a user name but no password, and the remote server requests a password, the program interpreting the FTP URL should request one from the user.