WordPress at a glance
function is not described

users_can_register_signup_filter() WP 3.0.0

Check whether users can self-register, based on Network settings.

No Hooks.

Return

true|false. Null. Nothing.

Usage

users_can_register_signup_filter();

Changelog

Since 3.0.0 Introduced.

Code of users_can_register_signup_filter() WP 5.7

<?php
function users_can_register_signup_filter() {
	$registration = get_site_option( 'registration' );
	return ( 'all' === $registration || 'user' === $registration );
}