In OS X, website developers can aid Safari in discovering searchable content by including an OpenSearch description document on their site, conforming to the format defined in the OpenSearch specification. After the user has visited a page on the website, the site will then show up in the Manage Websites panel of Safari’s Search Preferences, allowing the user to selectively enable or disable the Quick Website Search feature for individual websites. Although the use of OpenSearch is not strictly necessary (Safari’s heuristic is sometimes able to obtain the information it needs by other means, such as from the form metadata for search fields), it is strongly recommended that websites publish an OpenSearch description.

Note: Safari on iOS does not support OpenSearch.

<openSearch:totalResults>111</openSearch:totalResults>

<openSearch:startIndex>1</openSearch:startIndex>

<openSearch:itemsPerPage>50</openSearch:itemsPerPage>

<openSearch:totalResults>3297</openSearch:totalResults><openSearch:startIndex>1</openSearch:startIndex><openSearch:itemsPerPage>25</openSearch:itemsPerPage>

<openSearch:totalResults>3297</openSearch:totalResults><openSearch:startIndex>1</openSearch:startIndex><openSearch:itemsPerPage>25</openSearch:itemsPerPage>

<channel rdf:about="http://search.hatena.ne.jp/keyword?word=ABC&page=1">

<title>はてな検索: ABC</title>

<link>http://search.hatena.ne.jp/keyword?word=ABC&page=1</link>

<description>はてなキーワードから「ABC」の検索結果</description>

<openSearch:totalResults>60</openSearch:totalResults>

<openSearch:startIndex>1</openSearch:startIndex>

<openSearch:itemsPerPage>10</openSearch:itemsPerPage>

Note that OpenSearch description URLs are ignored in Chrome if this file isn't placed in the webroot.

Also, in Chrome, you won't see the request in the developer tools because the request happens in the privileged browser process.

Use a network sniffer to detect it.