Developer credits
Git commits in Moodle 3.9.x by Nick Phillips
commit 7a2baafc9628598810075269bc69a3828415a064 Author: Nick Phillips <nick.phillips@otago.ac.nz> Date: Wed, 04 Mar 2020 11:16:41 +0800 Tag: v3.9.0-beta MDL-68103 theme_classic: hidden-print => d-print-none for BS4.