Old versions of Flink (especially version 0.8) are being frequently studied, downloaded, and used by new users (because google leads them there). I propose to guide folks to the latest stable release by adding a link on every documentation page in the old docs that links to the home page of the latest stable docs.
The redirect lives at flink.apache.org/q/stable-docs.html, and will need to be modified with each major release (e.g. when 1.2 is released).
This problem affects all releases before 1.1, but the stats show that 0.8, 0.9, 0.10, and 1.0 are the most important to deal with.