Gets and sets the property CallerReference. A unique number that ensures the request can't be replayed. If the CallerReference is new (no matter the content of the DistributionConfig object), a new distribution is created. If the CallerReference is a value you already sent in a previous request to create a distribution, and the content of the DistributionConfig is identical to the original request (ignoring white space), the response includes the same information returned to the original request. If the CallerReference is a value you already sent in a previous request to create a distribution but the content of the DistributionConfig is different from the original request, CloudFront returns a DistributionAlreadyExists error.

public string CallerReference { get; set; }