原型

admin_created_user_subject( $text )

源文件

路径:wp-admin/user-new.php

<?php
...
	$user_details = null;
	$user_email = wp_unslash( $_REQUEST['email'] );
	if ( false !== strpos( $user_email, '@' ) ) {
...
?>

其他

英文文档:https://developer.wordpress.org/reference/functions/admin_created_user_subject/