User blog comment:Kirkburn/Technical Update: October 1, 2013/@comment-3441771-20131002121836/@comment-126761-20131002171837

It's actually controlled by the message "wikiarelatedpages-heading" :) Indeed, it was coded under the name 'related pages', but we went with 'Read more' in the end, partly since 'related' depends on the way the wiki has been categorised.