From IndieWeb

rel-prev is the use of the HTML rel attribute on a hyperlink to the page previous to the current page with the value of "prev" to provide a way for consuming code to discover that link and navigate to it to show content previous to the current page; like a monthly archive page linking to the previous month, or a link from a homepage with a stream to an archive page of previous posts in the stream.

Note: You might also encounter rel="previous", this should still be supported by consumers for compatibility purposes. ([WHATWG HTML5)

See Also