IAM JSON policy elements: Id - Amazon Identity and Access Management
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IAM JSON policy elements: Id

The Id element specifies an optional identifier for the policy. The ID is used differently in different services.

For services that let you set an ID element, we recommend you use a UUID (GUID) for the value, or incorporate a UUID as part of the ID to ensure uniqueness. 

"Id": "cd3ad3d9-2776-4ef1-a904-4c229d1642ee"
Note

Some Amazon services (for example, Amazon SQS or Amazon SNS) might require this element and have uniqueness requirements for it. For service-specific information about writing policies, refer to the documentation for the service you're working with.