Ideas about the 5th byte (if len = 89)

[sonman]

For some reason Apple introduced a year ago an extra 5th byte into the location report (see 52.
In my cases it is always 0x00.

Any other observations ? Do you have an idea for what this byte is for ?

[fz6]

I looked back over ~40k reports for something else today, FWIW I have 16k 88-byte reports and 26k 89 byte reports. The extra byte is always 0x00 for me too.