Added user guide documentation to show how to use the @http parameter.

docs/getting-started/basic-usage.rst

@@ -117,17 +117,17 @@ same as the namespace of a service (e.g., "S3", "DynamoDb", etc.).
     $client = $sdk->createDynamoDb();
 
 Service-specific configuration values are a union of the service-specific
-values and the root-level values (i.e., service-specific values are shallow
-merged onto root level values).
+values and the root-level values (i.e., service-specific values are
+shallow-merged onto root level values).
 
 .. tip::
 
     It is highly recommended that you use the ``Sdk`` class to create clients
-    if you are utilizing multiple SDK clients in your application. The ``Sdk``
-    class will automatically utilize the same HTTP client for each SDK client,
-    allowing SDK clients for different services to perform non-blocking HTTP
-    requests. If the SDK clients do not use the same HTTP client, then HTTP
-    requests sent by the SDK client may cause inter-service promise
+    if you are utilizing multiple client instances in your application. The
+    ``Sdk`` class will automatically utilize the same HTTP client for each SDK
+    client, allowing SDK clients for different services to perform non-blocking
+    HTTP requests. If the SDK clients do not use the same HTTP client, then
+    HTTP requests sent by the SDK client may cause inter-service promise
     orchestration to block.
 
 
@@ -172,6 +172,27 @@ operation in the SDK's API Documentation (e.g., see the API docs for
 `putObject operation <http://docs.aws.amazon.com/aws-sdk-php/v3/api/api-s3-2006-03-01.html#putobject>`__).
 
 
+HTTP Handler Options
+~~~~~~~~~~~~~~~~~~~~
+
+It's also possible to fine tune how the underlying HTTP handler executes the
+request by using the special ``@http`` parameter. The options you can include
+in the ``@http`` parameter are the same as the ones you can set when you
+instantiate the client with the :ref:`"http" client option <config_http>`.
+
+.. code-block:: php
+
+    // Send the request through a proxy.
+    $result = $s3Client->putObject([
+        'Bucket' => 'my-bucket',
+        'Key'    => 'my-key',
+        'Body'   => 'this is the body!',
+        '@http'  => [
+            'proxy' => 'http://192.168.16.1:10'
+        ]
+    ]);
+
+
 Asynchronous Requests
 ---------------------
 

docs/guide/commands.rst

@@ -47,7 +47,7 @@ The following examples are functionally equivalent:
     $result = $s3Client->execute($command);
 
 
-Command Parameters
+Command parameters
 ------------------
 
 When you create a command using a client's ``getCommand()`` method, it does not
@@ -71,6 +71,23 @@ opportunity to modify the command object before executing the command.
     $result = $s3Client->execute($command);
 
 
+HTTP handler options
+--------------------
+
+All commands support the special ``@http`` parameter. Using this parameter,
+it's possible to fine tune how the underlying HTTP handler executes the
+request. The options you can include in the ``@http`` parameter are the same as
+the ones you can set when you instantiate the client with the
+:ref:`"http" client option <config_http>`.
+
+.. code-block:: php
+
+    // Configures the command to be delayed by 500 milliseconds.
+    $command['@http'] = [
+        'delay' => 500,
+    ];
+
+
 Command HandlerList
 -------------------
 
@@ -264,8 +281,8 @@ objects, so we will need to map over the ``SplFileInfo`` objects to return
     $promise->then(function() { echo "Done\n"; });
 
 
-CommandPool Config
-~~~~~~~~~~~~~~~~~~
+CommandPool configuration
+~~~~~~~~~~~~~~~~~~~~~~~~~
 
 The ``Aws\CommandPool`` constructor accepts various configuration options.
 

docs/guide/configuration.rst

@@ -275,6 +275,8 @@ them in FIFO order.
     $client->listTables();
 
 
+.. _config_http:
+
 http
 ~~~~