diff --git a/server_installation/topics/network/outgoing.adoc b/server_installation/topics/network/outgoing.adoc
index 761fdcfec9..2906052b74 100644
--- a/server_installation/topics/network/outgoing.adoc
+++ b/server_installation/topics/network/outgoing.adoc
@@ -135,6 +135,46 @@ Note that one needs to encode `"` characters with `\"`.
 </spi>
 ----
 
+[[_proxy_env_vars]]
+==== Using standard environment variables
+
+Alternatively, it is possible to use standard environment variables to configure the proxy mappings, that is `HTTP_PROXY`, `HTTPS_PROXY`
+and `NO_PROXY` variables.
+
+The `HTTP_PROXY` and `HTTPS_PROXY` variables represent the proxy server that should be used for all outgoing HTTP requests.
+{project_name} does not differ between the two. If both are specified, `HTTPS_PROXY` takes the precedence regardless of
+the actual scheme the proxy server uses.
+
+The `NO_PROXY` variable is used to define a comma separated list of hostnames that should not use the proxy.
+If a hostname is specified, all its prefixes (subdomains) are also excluded from using proxy.
+
+Take the following example:
+[source]
+----
+HTTPS_PROXY=https://www-proxy.acme.com:8080
+NO_PROXY=google.com,login.facebook.com
+----
+In this example, all outgoing HTTP requests will use `\https://www-proxy.acme.com:8080` proxy server except for requests
+to for example `login.google.com`, `google.com`, `auth.login.facebook.com`. However, for example `groups.facebook.com` will be routed
+through the proxy.
+
+NOTE:  The environment variables can be lowercase or uppercase. Lowercase takes precedence. For example if both `HTTP_PROXY` and
+       `http_proxy` are defined, `http_proxy` will be used.
+
+If proxy mappings are defined using the subsystem configuration (as described above), the environment variables are not
+considered by {project_name}. This scenario applies in case no proxy server should be used despite having for example `HTTP_PROXY`
+environment variable defined. To do so, you can specify a generic no proxy route as follows:
+[source,xml]
+----
+<spi name="connectionsHttpClient">
+    <provider name="default" enabled="true">
+        <properties>
+            <property name="proxy-mappings" value=".*;NO_PROXY"/>
+        </properties>
+    </provider>
+</spi>
+----
+
 [[_truststore]]
 ==== Outgoing HTTPS Request Truststore
 
diff --git a/upgrading/topics/keycloak/changes.adoc b/upgrading/topics/keycloak/changes.adoc
index ffe5e76a73..f0c34a7beb 100644
--- a/upgrading/topics/keycloak/changes.adoc
+++ b/upgrading/topics/keycloak/changes.adoc
@@ -1,5 +1,16 @@
 == Migration Changes
 
+=== Migrating to 16.0.0
+
+==== Proxy environment variables
+
+{project_name} now respects the standard `HTTP_PROXY`, `HTTPS_PROXY` and `NO_PROXY` environment variables for outgoing
+HTTP requests. This change could lead to unexpected use of a proxy server if you have for example the `HTTP_PROXY` variable defined but have no
+explicit proxy mappings specified in your SPI configuration. To prevent {project_name} from using those environment variables,
+you can explicitly create a no proxy route for all requests as `.*;NO_PROXY`.
+
+For more details, see the link:{installguide_link}#_proxy_env_vars[related chapter in the {installguide_name}].
+
 === Migrating to 14.0.0
 
 ==== Client Policies Migration