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If the display_std_form fucntion is run then it creates a Authentication displaystdform object and then includes the default login form unless the login form in config exists
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If the display_err_form fucntion is run then it creates a Authentication displayerrform object and then includes the default errorform unless the error form in config exists
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This is run when plugins want to determine if another plugin recognise a username, a Authentication lookupuser object is created then parsed to it.