The document is from 2008 and the CC0 licence was started in 2007, finalized 2009.<p><a href="https:&#x2F;&#x2F;en.m.wikipedia.org&#x2F;wiki&#x2F;Creative_Commons_license#Zero_.2F_public_domain" rel="nofollow">https:&#x2F;&#x2F;en.m.wikipedia.org&#x2F;wiki&#x2F;Creative_Commons_license#Zer...</a>