WordPress Version: 5.9
/**
* Validates user sign-up name and email.
*
* @since MU (3.0.0)
*
* @return array Contains username, email, and error messages.
* See wpmu_validate_user_signup() for details.
*/
function validate_user_form()
{
return wpmu_validate_user_signup($_POST['user_name'], $_POST['user_email']);
}