Updated the documentation.

Author: Michael Khmelnitsky

doc_source/sns-document-history.md

@@ -5,7 +5,7 @@ The following table lists changes to the *Amazon Simple Notification Service Dev
 
 | Date | Documentation Update | 
 | --- | --- | 
-| September 5, 2019 | Revised the information in the [Send Custom Platform\-Specific Payloads to Mobile Devices](sns-send-custom-platform-specific-payloads-mobile-devices.md) section\. | 
+| September 10, 2019 |  [\[See the AWS documentation website for more details\]](http://docs.aws.amazon.com/sns/latest/dg/sns-document-history.html)  | 
 | August 29, 2019 | Revised the information in the following sections: [\[See the AWS documentation website for more details\]](http://docs.aws.amazon.com/sns/latest/dg/sns-document-history.html) | 
 | August 26, 2019 |  [\[See the AWS documentation website for more details\]](http://docs.aws.amazon.com/sns/latest/dg/sns-document-history.html)  | 
 | August 19, 2019 | Added the [Allow a CloudWatch Alarm in an AWS Account to Publish to an Amazon SNS Topic in a Different AWS Account](sns-access-policy-use-cases.md#sns-allow-cloudwatch-alarm-to-publish-to-topic-in-another-account) section\. | 

doc_source/sns-release-notes.md

@@ -5,6 +5,7 @@ The following table lists Amazon SNS feature releases and improvements\. For cha
 
 | Date | Feature Release | 
 | --- | --- | 
+| September 10, 2019 | Amazon SNS supports the apns\-push\-type header field for mobile notifications sent through APNs\. For more information, see [Sending Messages to APNs as Background Notifications](sns-send-custom-platform-specific-payloads-mobile-devices.md#mobile-push-send-message-apns-background-notification)\. | 
 | July 24, 2019 | You can troubleshoot messages passing through Amazon SNS topics using AWS X\-Ray\. For more information, see [Troubleshooting Amazon Simple Notification Service Topics Using AWS X\-Ray](sns-troubleshooting-using-x-ray.md) section\.  | 
 | July 5, 2019 |  [\[See the AWS documentation website for more details\]](http://docs.aws.amazon.com/sns/latest/dg/sns-release-notes.html)  | 
 | May 16, 2019 |  [\[See the AWS documentation website for more details\]](http://docs.aws.amazon.com/sns/latest/dg/sns-release-notes.html)  | 

doc_source/sns-send-custom-platform-specific-payloads-mobile-devices.md

@@ -43,6 +43,26 @@ The following example shows a message to send to subscribed mobile endpoints on
 one of the notification platforms.",     
   "APNS": "{\"aps\":{\"alert\": \"Check out these awesome deals!\",\"url\":\"www.amazon.com\"} }",
   "FCM": "{\"data\":{\"message\":\"Check out these awesome deals!\",\"url\":\"www.amazon.com\"}}",
-  "ADM": "{ \"data\": { \"message\": \"Check out these awesome deals!\",\"url\":\"www.amazon.com\" }}" 
+  "ADM": "{\"data\":{\"message\":\"Check out these awesome deals!\",\"url\":\"www.amazon.com\"}}" 
 }
-```
+```
+
+## Sending Messages to APNs as Background Notifications<a name="mobile-push-send-message-apns-background-notification"></a>
+
+Amazon SNS sets the `apns-push-type` APNs header to `alert` or `background` depending on the `content-available` field in your APNs JSON payload configuration\. For more information, see [Pushing Background Updates to Your App](https://developer.apple.com/documentation/usernotifications/setting_up_a_remote_notification_server/pushing_background_updates_to_your_app) in the APNs documentation\.
++ An `alert` APNs notification informs your users by displaying an alert message, playing a sound, or adding a badge to your application’s icon\.
++ A `background` APNs notification wakes up or instructs your application to act upon the content of the notification, without informing the user\.
+
+**Important**  
+If Amazon SNS sends a raw configuration object for APNs, you must specify the appropriate `content-available` field within the configuration object\.
+If the value of the `content-available` field isn’t an integer or a Boolean, the notification defaults to `alert`\.
+
+The following is an example raw configuration object\.
+
+```
+{
+  "APNS": "{\"aps\":{\"content-available\":1},\"Foo1\":\"\Bar\",\"Foo2\":123}"
+}
+```
+
+In this example, Amazon SNS sets the `apns-push-type` APNs header to `alert` for the message\. When Amazon SNS detects that `content-available` is set to `1`, it sets the header to `background.`