docs: clarify NO_PROXY env variable functionality

Reported-by: Kirill Marchuk
Fixes #2773
Closes #2911

3 files changed, 10 insertions, 9 deletions

diff --git a/docs/cmdline-opts/page-footer b/docs/cmdline-opts/page-footer
index 89bface65..33d800b14 100644
--- a/docs/cmdline-opts/page-footer
+++ b/docs/cmdline-opts/page-footer
@@ -20,9 +20,10 @@ protocol that curl supports and as specified in a URL. FTP, FTPS, POP3, IMAP,
 SMTP, LDAP etc.
 .IP "ALL_PROXY [protocol://]<host>[:port]"
 Sets the proxy server to use if no protocol-specific proxy is set.
-.IP "NO_PROXY <comma-separated list of hosts>"
-list of host names that shouldn't go through any proxy. If set to an asterisk
-\&'*' only, it matches all hosts.
+.IP "NO_PROXY <comma-separated list of hosts/domains>" list of host names that
+shouldn't go through any proxy. If set to an asterisk \&'*' only, it matches
+all hosts. Each name in this list is matched as either a domain name which
+contains the hostname, or the hostname itself.
 
 This environment variable disables use of the proxy even when specified with
 the --proxy option. That is
diff --git a/docs/libcurl/opts/CURLOPT_NOPROXY.3 b/docs/libcurl/opts/CURLOPT_NOPROXY.3
index 8ca0580a2..0d3ce229c 100644
--- a/docs/libcurl/opts/CURLOPT_NOPROXY.3
+++ b/docs/libcurl/opts/CURLOPT_NOPROXY.3
@@ -52,7 +52,9 @@ brackets:
 The application does not have to keep the string around after setting this
 option.
 .SH "Environment variables"
-See \fICURLOPT_PROXY(3)\fP
+If there's an environment variable called \fBno_proxy\fP (or \fBNO_PROXY\fP),
+it will be used if the \fICURLOPT_NOPROXY(3)\fP option is not set. It works
+exactly the same way.
 .SH DEFAULT
 NULL
 .SH PROTOCOLS
diff --git a/docs/libcurl/opts/CURLOPT_PROXY.3 b/docs/libcurl/opts/CURLOPT_PROXY.3
index ca7ae6936..97818e920 100644
--- a/docs/libcurl/opts/CURLOPT_PROXY.3
+++ b/docs/libcurl/opts/CURLOPT_PROXY.3
@@ -5,7 +5,7 @@
 .\" *                            | (__| |_| |  _ <| |___
 .\" *                             \___|\___/|_| \_\_____|
 .\" *
-.\" * Copyright (C) 1998 - 2017, Daniel Stenberg, <daniel@haxx.se>, et al.
+.\" * Copyright (C) 1998 - 2018, Daniel Stenberg, <daniel@haxx.se>, et al.
 .\" *
 .\" * This software is licensed as described in the file COPYING, which
 .\" * you should have received as part of this distribution. The terms
@@ -79,10 +79,8 @@ libcurl respects the proxy environment variables named \fBhttp_proxy\fP,
 proxy for that URL scheme. So for a "FTP://" URL, the \fBftp_proxy\fP is
 considered. \fBall_proxy\fP is used if no protocol specific proxy was set.
 
-If \fBno_proxy\fP (or \fBNO_PROXY\fP) is set, it can specify a list of host
-names to not use a proxy for (even if one of the previous mention variables
-are set). That is the exact equivalent of setting the \fICURLOPT_NOPROXY(3)\fP
-option.
+If \fBno_proxy\fP (or \fBNO_PROXY\fP) is set, it is the exact equivalent of
+setting the \fICURLOPT_NOPROXY(3)\fP option.
 
 The \fICURLOPT_PROXY(3)\fP and \fICURLOPT_NOPROXY(3)\fP options override
 environment variables.