add a note about temporary resource names

website/source/docs/builders/amazon-ebs.html.md

@@ -28,6 +28,10 @@ bit.
 The builder does *not* manage AMIs. Once it creates an AMI and stores it in your
 account, it is up to you to use, delete, etc. the AMI.
 
+-> **Note:** Temporary resources are, by default, all created with the prefix
+`packer`. This can be useful if you want to restrict the security groups and
+key pairs Packer is able to operate on.
+
 ## Configuration Reference
 
 There are many configuration options available for the builder. They are

website/source/docs/builders/amazon-ebsvolume.html.md

@@ -24,6 +24,10 @@ instance while the image is being created.
 The builder does *not* manage EBS Volumes. Once it creates volumes and stores
 it in your account, it is up to you to use, delete, etc. the volumes.
 
+-> **Note:** Temporary resources are, by default, all created with the prefix
+`packer`. This can be useful if you want to restrict the security groups and
+key pairs Packer is able to operate on.
+
 ## Configuration Reference
 
 There are many configuration options available for the builder. They are

website/source/docs/builders/amazon-instance.html.md

@@ -28,6 +28,10 @@ created. This simplifies configuration quite a bit.
 The builder does *not* manage AMIs. Once it creates an AMI and stores it in
 your account, it is up to you to use, delete, etc. the AMI.
 
+-> **Note:** Temporary resources are, by default, all created with the prefix
+`packer`. This can be useful if you want to restrict the security groups and
+key pairs packer is able to operate on.
+
 -> **Note:** This builder requires that the [Amazon EC2 AMI
 Tools](https://aws.amazon.com/developertools/368) are installed onto the
 machine. This can be done within a provisioner, but must be done before the