At Le Wiki de la Grisaia, you have the option to create an account. Doing so requires a username and a valid password. You do not need an account to edit here. If you choose to edit without a registered account, your numerical IP address will be visible to anyone looking at your contributions. This is due to the nature of the MediaWiki software. With an account, this is replaced by your desired username.
When registering an account on Le Wiki de la Grisaia, you also have the option to give your email address and real name. These are entirely optional, and if you do include them, Le Wiki de la Grisaia will not use them for profit nor disclose your information to other websites. They are also not visible to other users. Your real name can be used to provide credit to you for your work, and your email address will allow other users to send you emails through Special:EmailUser. Through using this function, the sender will not see your email address. Emails can also be used for password recovery. If you forget your password, Le Wiki de la Grisaia will send you an automated email with steps to choose a new one.