Washington: The National Security Agency (NSA) has released a guide to `help you understand how to use the Internet more efficiently`.
The guide to `Internet Research` is a `how-to` book for its agents looking to get the most out of Google, Yahoo and other Web search tools.
The guidebook, which was stamped `For Official Use Only` offers a number of tips for the spy in training.
According to Fox News, the guidebook also offers suggestions on how to find spreadsheets full of passwords in Russia : Type "filetype:xls site:ru login.
The 643-page tome, called Untangling the Web: A Guide to Internet Research, was last updated in 2007, so the search engine advice it offers is often outdated.