http://www.confreaks.com/videos/434-rubyconf2010-maintaining-balance-while-reducing-duplication
At 44 minutes he has a slide
talk-maintaining-balance-while-removing-duplication#dry-definition1 Every piece of knowledge must have a single, unambiguous, authoritative representation within a system
This is not really about duplicated strings of characters.
DRY is about duplicated concepts talk-maintaining-balance-while-removing-duplication#dry-definition1