Although I do not currently use read more tags on this blog one of my clients does. I decided that it was a waste of PageRank to have the more tags followed and went about finding some information on how add nofollow to the links. But I could not find any, after a good couple of hours of tweaking I figured out how to do it, here is a quick tutorial:
More Tag Nofollow Fix for Versions 2.1, 2.2 and 2.3
You need to make changes to the post template file in the WP includes folder. On line 124 you will see the following line of code:
$output .= ‘ <a href=”‘. get_permalink() . “#more-$id” class=”more-link”>$more_link_text</a>”;
You need to add the nofollow tag just before the link text. Simply replace the existing line of code with this one:
$output .= ‘ <a href=”‘. get_permalink() . “#more-$id” class=”more-link” rel=”nofollow”>$more_link_text</a>”;
Once you save the file all of your more tag links will be nofollowed.
I do not think that this will make a huge amount of difference to your search engine rankings, but PageRank is precious and it could help prevent some of your posts being dropped from the search results.