Merge pull request #531 from moxiegirl/484-version-fix

docs: clarify minimum docker version for use with v2 API

docs/deploying.md

@@ -148,8 +148,15 @@ information on making this image production ready.
 
 ## Understand production deployment
 
+The Docker Registry 2.0 only accepts connections from a Docker client that is
+version 1.6.0 or newer. This means, for example, if you are deploying in a
+environment with 1.5.X clients you'll need to either upgrade them or deploy an
+older version of the Docker Registry to support them. For information on how to
+do this, see [Configure Nginx with a v1 and v2
+registry](#configure-nginx-with-a-v1-and-v2-registry) on this page.
+
 When deploying a registry for a production deployment you should consider these
-factors:
+key factors:
 
 <table>
   <tr>

docs/index.md

@@ -15,7 +15,7 @@ Docker Registry is the core technology behind the Docker Hub. You can run your o
  - **Pluggable storage drivers**: Images can be stored in Amazon S3, Microsoft Azure or the local filesystem.
  - **Webhook notifications**: When an image is pushed to your registry, webhooks can fire off to launch CI builds, send notifications to IRC, etc.
 
-To get started with your own Docker Registry, head over to the instructions on how to [deploy a registry](deploying.md).
+You can only connect to a 2.0 Docker Registry with a Docker client that is version 1.6.0 or newer. To get started with your own Docker Registry, refer to the instructions on [how to deploy a registry](deploying.md).
 
 ## Understanding the registry