这些信息根本没有暴露给 javascript，它很少使用(永远不会，因为它不可用，但它会 很少使用)它被认为不足以添加到 javascript 对象模型中，我想......对于任何很少使用的功能都被遗漏了.

This information simply isn't exposed to javascript, it is so rarely used (well never since it isn't available, but it would be rarely used) that it wasn't deemed important enough to add to the javascript object model I suppose...same for any very rarely used feature left out of anything.

当然，出于安全原因，它也可能被排除在外......我目前没有足够的创造力来提出一个，但我相信那里也有一个漏洞利用.

Of course, it could have also been left out for security reasons...I'm not creative enough to come up with one at the moment, but I'm sure there's an exploit to be had there as well.