cwh_link_to_next is a Textpattern plugin that provides a replacement tag for <txp:link_to_next /> that includes a new format attribute which provides the ability to set the link format as a link tag suitable for placing in the head of any individual article page on your site. You can do this by setting the format attribute like so:
<txp:cwh_link_to_next title="Next" format="link" />
which will produce something similar to:
<link rel="next" href="http://example.com/article/2/next-post" title="Next Post" />
Note that when used as a single tag without the format attribute specified:
<txp:cwh_link_to_next />
if will produce a plain text link much in the same way as <txp:link_to_next />:
http://example.com/article/2/next-post
Finally, it can also be used as a container tag in the same manner as <txp:link_to_next /> if no format value is specified:
<txp:cwh_link_to_next> ...Text or Tag... </txp:cwh_link_to_next>
If you do specify a link value for the format attribute while used as a container tag, it will still produce a link tag.
This tag also shares all of the same attributes as <txp:link_to_next />. For a complete list of applicable attributes, see this Textbook entry.
For a further explanation of the benefits of using link tags for your site's navigation, please see Day 9: Providing additional navigation aids from Mark Pilgrim's Dive Into Accessibility.