The referring page a user came from (REFERER).

用户所来自的引用页(REFERER)。

Search engines, key phrases and key words (REFERER).

搜索引擎、关键短语和关键字 (REFERER)。

However, in some cases (notably the HTTP Referer header), it is awkward to carry out the attack by using a browser.

尽管，在一些情况下(特别是HTTP referer头)，很难利用浏览器执行攻击。