The Google Blog has a basic but clear explanation of the robots exclusion protocol. In this blog post, Google explained how the NOINDEX, NOFOLLOW, NOARCHIVE and NOSNIPPET META tags function. In short:

• NOINDEX tag tells Google not to index a specific page
• NOFOLLOW tag tells Google not to follow the links on a specific page
• NOARCHIVE tag tells Google not to store a cached copy of your page
• NOSNIPPET tag tells Google not to show a snippet (description) under your Google listing, it will also not show a cached link in the search results

Related Topics: Google: SEO | SEO: Blocking Spiders | SEO: General

About The Author: Barry Schwartz is Search Engine Land's News Editor and owns RustyBrick, a NY based web consulting firm. He also runs Search Engine Roundtable, a popular search blog on very advanced SEM topics. Barry's personal blog is named Cartoon Barry and he can be followed on Twitter here. For more background information on Barry, see his full bio over here. See more articles by Barry Schwartz