Environment variables understood by Ansible

Where can I find a list of environment variables that modify Ansible parameters? I am talking about the environment variables one sets before calling Ansible, eg ‘ENV_VAR1=something ansible -i …’.

In 2.4 we are adding a new command line tool 'ansible-config' which
can dump all configuration settings, including which environment
variables/ini entries/etc affect it.

The list in previous versions lives in
https://github.com/ansible/ansible/blob/stable-2.3/lib/ansible/constants.py

Super! Thanks for the info.