http://www.cisco.com/c/en/us/support/web/tools/help/command_search_best_practices.html
Best Practices for searching Commands
All commands are searchable via Cisco.com search.
To narrow your search results, add the software name (for example, IOS, XR, ASA) and the software version.
Here are some additional techniques to reduce the number of search results:
Filter by Document Type:
“Document Type” filter is sorted alphabetically.
Select your Product:
“Product” filter is sorted by the number of results available as part of the search result set.
More Search general tips