rel=\"search\" attribute value specifies that the linked page can be used to search relevant content in the current page.
The search page can be about the topics in the current page or the entire website.
rel="search" on an <a> element.
This link is a Google search query with a filter for the current site.
To discover more: <a rel="search" href="https://google.com/search?q=site:dofactory.com" target="_blank">Search here</a>.
The rel attribute defines the relationship between the current page and the linked page.
rel="search" value specifies that the linked page is designed to search the current page for related content, resources, and more.
<tagname rel="search" />
These elements accept the search value on the rel attribute.
|<a>||Specifies an anchor link -- see example above|
|<area>||Creates clickable areas inside an image map.|
|<form>||Specifies an HTML form.|
|<link>||Links a resource to the current page|
Here is when rel support started for each browser: