AES/GCM Encryption

Hi,
I am going through KMIP 1.2 spec and saw the details of Cryptographic Parameters for Encryption operation.

In GCM there is one parameter called AAD (Additional Authenticated Data) which is optional.

But in KMIP spec there is nothing like AAD for GCM.

Is KMIP missed this or not included in spec for some purpose ?

Waiting for your response and Thanks in advance

Regards,

Nitin