Developer credits
Git commits in Moodle 3.1.x by Lee Campbell
commit 3508f1b8e20f9664cfe26cfd0bcb318ee024b708 Author: Lee Campbell <lee@learningpool.com> Date: Thu, 20 Oct 2016 23:02:33 +0800 Tag: v3.1.3 MDL-56323 core_user: User profile field default value not on signup page