Manual:Parameters to Special:UserLogin/signup

From mediawiki.org
parameter type purpose
wpName string Username for account
wpEmail string Email to attach to account for sending password (and resets)
wpReason string Reason for creating account
wpCreateaccountMail boolean setting to true will email a password to wpEmail (and not ask you to enter one)
wpIgnoreTitleBlacklist boolean setting to true will ignore any Extension:TitleBlacklist conflicts
wpIgnoreAntiSpoof boolean setting to true will ignore any Extension:AntiSpoof conflicts