For sys admins and devs, clarify that you can create OR edit server-vars.yml

https://mail.google.com/mail/u/0/#inbox/1563007c0f85d32a

For config options that require changes to server-vars.yml, make it clearer that the file might not already exist, and can be created OR edited.
In addition, clarify throughout that the file does not already include all possible config settings, and that you can add them if they are not already present

Numerous queries come in from people who are not able to find server-vars.yml, or who don't see the setting they need to change in that file already. They aren't sure that it's ok to add it.
https://groups.google.com/forum/#!topic/openedx-ops/ZgtpBUtiEH0
Also, find out from the devops folks if this file (pointed to in the thread linked above) is a good model for people to use.
https://github.com/edx/configuration/blob/master/playbooks/roles/edxapp/defaults/main.yml