# ENVIRONMENT
The environment variables can be specified in lower case or upper case. The
lower case version has precedence. `http_proxy` is an exception as it is only
-available in lower case.
+available in lower case. (Note that some systems, like Windows, do not
+differentiate between environment variables using different case.)
Using an environment variable to set the proxy has the same effect as using
the --proxy option.
These proxy variables are also checked for in their uppercase versions, except
the **http_proxy** one which is only used lowercase. Note also that some
-systems actually have a case insensitive handling of environment variables and
-then of course **HTTP_PROXY** still works.
+systems (like Windows) have a case insensitive handling of environment
+variables and then of course **HTTP_PROXY** still works.
An exception exists for the WebSocket **ws** and **wss** URL schemes, where
libcurl first checks **ws_proxy** or **wss_proxy** but if they are not set, it