@clstokes, in [Amazon ServerCertificateMetadata](http://docs.aws.amazon.com/IAM/latest/APIReference/API_ServerCertificateMetadata.html) they have three id-ish fields:
* ```Arn``` - this one must be used when [setting LB certificate](http://docs.aws.amazon.com/ElasticLoadBalancing/latest/APIReference/API_SetLoadBalancerListenerSSLCertificate.html), so it's necessary to have it passed to ```grid-api``` level.
* ```ServerCertificateName``` - this one is used as unique identifier, for example to get a certificate metadata.
* ```ServerCertificateId``` - this one is not used so far. I'm not sure if it might be needed in future for other services.

So on ```grid-api``` level I renamed "arn" to a "certificateResourceId". I understand it's quite misleading to have so many identifiers within one object, but that's how Amazon API works.