The Robots Exclusion Protocol includes the following exclusion attributes:
- NOINDEX tag tells the Google bot not to index a specific page;
- NOFOLLOW tag tells the Google bot not to follow the links on a specific page;
- NOARCHIVE tag tells the Google bot not to store a cached copy of the page;
- NOSNIPPET tag tells the Google bot not to show a snippet under your Google listing.
Exclusion can be implemented through the robots.txt file or the meta of a selected page using the protocol:
<meta name='robots' content='nofollow' />
For a more detailed explanation see the Robots Exclusion Protocol definition on Google.