If you want to control how users register for a member site, it’s a good idea to remove the registration link on on the login screen.
/*remove registration link from login page*
add_filter('register','no_register_link');
function no_register_link($url){
return '';
}
To hide both register link and lost password (somewhat dangerous):
/**
* add custom admin login CSS to hide the Lost Password and Register links
*/
function isa_login_css() {
echo '';
}
add_action('login_head', 'isa_login_css');






