Question about resetting sensors

[nomis52]

The standard states:

"The SET_COMMAND may be used in conjunction with SENSOR_VALUE to reset or clear a given sensor. When a sensor is successfully reset the values for Present, Lowest/Highest, Recorded values in the response message shall all be equal. "

What does this actually mean? I'd read that to say that at the moment of resetting, the current value should be copied into present and lowest, highest & recorded set to the current value.

But further in the standard it states:

"Recorded Value:
... Support for this data is optional. If this value is not supported, then this field shall be set to 0x0000.
"""

The same text is used for highest & lowest as well.

So if the responder doesn't support recording values or highest / lowest, what should the value of the recorded/highest/lowest field be? This is one of the last tests I need to write and I'm having a hard time deciding what behavior to expect.

There is the separate issue of what to return when all sensors (0xff) have but that's been discussed before.


Simon