There's a similar quirk with the env variables used to set a proxy hostname - http_proxy vs HTTP_PROXY. On Unix environment variable names are case sensitive, $

There's a similar quirk with the env variables used to set a proxy hostname - http_proxy vs HTTP_PROXY. On Unix environment variable names are case sensitive, $foo is distinct from $FOO. The strong convention is to use upper-case only. Some early command line http client (possible lynx) chose to buck the trend and used lower-case. Now some programs check the upper-case variant, some the lower, and some check both. So if you set one, you should set the other to avoid confusion. https://wiki.archlinux.org/index.php/proxy_settings#Environment_variables https://wiki.archlinux.org/index.php/proxy_settings#Environm... Does anyone know of a full write-up of the history of this?