AD5734R Read data format

I am designing a UVM agent to mimic the AD5734R. I read that the internal registers are 16b and can be read out. I see the Read Timing Diagram shows SDO returns 24b of data. 

What is not clear to me is the SDO data format. Does the SDO look like R, 0, R2-0, A2-0, Data? or 8b of don't care followed by the data? or something else?