Ubuntu Precise Pangolin Release Notes
wiki.ubuntu.com/PrecisePangolin/ReleaseNotes
From the page
Saved with the link. Notes from 2007 to 2016 are mostly the page's own words, so this is probably an excerpt.
These release notes for Ubuntu 12.04 (Precise Pangolin) provide an overview of the release and document the known issues with Ubuntu 12.04 and its flavors.