Where is the minimum Linux kernel version requirement documented. For 18.02 the version should be kernel version 3.2 or greater.
Since 3.2 will EOL if May, for 18.05 the requirement will advance to next LTS kernel which is 3.16. It would be good to put in a deprecation warning about that in 18.02 release; for warned is for armed. Since 3.16 is good until April 2020, it will be several more releases until the horizon can be moved again.
