rel="next" attribute value on a link specifies that the linked page is the next page of the current page in a series of pages.
rel="next" on an <a> element.
This link opens the next page in a list of pages.
Continue to the <a rel="next" href="/html/rel/bookmark">next page</a>
The rel attribute defines the relationship between the current page and the linked page.
rel="next" value specifies that the linked page is the next page of the current page.
This value is for content that needs pagination for a list of articles, topics, blog entries, etc.
<tagname rel="next" />
These elements accept the next 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|
The rel attribute value can greatly affect search engine optimization.
This value helps search engine in identifying that the page belongs to a series and get relevant content.
Search engines put highest ranking on the first page recognized from the series.
This avoids duplicate content issue on different pages within the series.
Here is when rel support started for each browser: