可以使用空格；除了半形句點、連結線和底線（ . - _ ）之外，不可使用其他符號。請不要使用中文。

A valid e-mail address. All e-mails from the system will be sent to this address. The e-mail address is not made public and will only be used if you wish to receive a new password or wish to receive certain news or notifications by e-mail.