Bernt
In section 10.6.3 we clearly state that a GET:DMX_START_ADDRESS request sent to a root or sub-device that has a footprint of zero shall return a value of 0xFFFF.
One could argue that NACKing any GET/SET DMX_START_ADDRESS with a NR_DATA_OUT_OF_RANGE is still supporting the PID, and our definition in table A-17 is entirely consistent with having a footprint of zero.
(definition is "Value out of range or not supported)
This would be preferable to a NACK:NR_UNKNOWN_PID as it avoids any argument that you haven't supported what many expect to be a Mandatory Pid.
My preference would be for us to remove the "option" in Table A-3 and point people back to the "shall" statement in 10.6.3, and add clarification on how to NACK the SET: request.
Peter
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