Google Allows You To Disable The Sitelinks Search Box, To Search Within The Google Search Results
Google's new meta tag, nositelinkssearchbox, disables the sitelinks search box.
In early September, Google introduced the Sitelinks search box that gives webmaster the ability to control how Google handles searches conducted within the search within this site, in the Google search results snippet area. Google is now letting webmasters disable the feature completely.
For example, if you search for in Google, Google will add a box under the first YouTube result, that lets you search within just the youtube.com domain, this also known as a site command search. Developers have more control over how those searches work and if they land on your internal site search pages or not.
Now, as spotted by Menashe Avramov, Google added a new feature to disable the sitelinks search box from showing up completely.
You can disable the Sitelinks Search feature by using a new meta tag named nositelinkssearchbox. Here is the meta tag:
Webmasters who add this tag to their site, will communicate to Google not to show a sitelinks search box when your site appears in the search results. The sitelinks search box will be disabled as part of the normal Googlebot crawling and processing of the page, which can take a few weeks depending on the site and other factors.