See fetch(3) for a description of additional environment variables, including FETCH_BIND_ADDRESS, FTP_LOGIN, FTP_PASSIVE_MODE, FTP_PASSWORD, FTP_PROXY, ftp_proxy, HTTP_ACCEPT, HTTP_AUTH, HTTP_PROXY, http_proxy, HTTP_PROXY_AUTH, HTTP_REFERER, HTTP_USER_AGENT, NETRC, NO_PROXY, no_proxy, SSL_CA_CERT_FILE, SSL_CA_CERT_PATH, SSL_CLIENT_CERT_FILE, SSL_CLIENT_KEY_FILE, SSL_CRL_FILE, SSL_ALLOW_SSL3, SSL_NO_TLS1, SSL_NO_TLS1_1, SSL_NO_TLS1_2, SSL_NO_VERIFY_HOSTNAME and SSL_NO_VERIFY_PEER.