可以自动检查一个用户名或电子邮件地址是否已经不再使用，验证表单而无需刷新页面，甚至提交表单并动态显示一个结果。

You could automatically check that a user name or email address is not already in use, validate the form without refreshing the page, or even submit the form and display a result dynamically.

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用户是否可以注册，以创建自己的用户名，或者名称基于用户的电子邮件地址或其他可能已知的构造(名的第一个字母加上姓)？

Can users register to create their own user names, or are the names based on users' E-mail addresses or some other potentially well-known construct (first letter of first name plus last name)?

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