WordPress at a glance
filter is not described

illegal_user_logins filter-hook . WP 4.4.0

Filters the list of disallowed usernames.

Usage

add_filter( 'illegal_user_logins', 'filter_function_name_9014' );
function filter_function_name_9014( $usernames ){
	// filter...

	return $usernames;
}
$usernames(array)
Array of disallowed usernames.

Changelog

Since 4.4.0 Introduced.

Where the hook is called

wp_insert_user()
illegal_user_logins
register_new_user()
illegal_user_logins
WP_REST_Users_Controller::check_username()
illegal_user_logins
wpmu_validate_user_signup()
illegal_user_logins
edit_user()
illegal_user_logins
wp-includes/user.php 1801
$illegal_logins = (array) apply_filters( 'illegal_user_logins', array() );
wp-includes/user.php 2723
$illegal_user_logins = (array) apply_filters( 'illegal_user_logins', array() );
wp-includes/rest-api/endpoints/class-wp-rest-users-controller.php 1255
$illegal_logins = (array) apply_filters( 'illegal_user_logins', array() );
wp-includes/ms-functions.php 500
$illegal_logins = (array) apply_filters( 'illegal_user_logins', array() );
wp-admin/includes/user.php 193
$illegal_logins = (array) apply_filters( 'illegal_user_logins', array() );

Where in WP core the hook is used WordPress

Usage not found.