What does FragDataBlockAuthReq do

[oedze]

In the FUOTA example program the "FragDataBlockAuthReq" is sent during filetransfer.

What does this command do? it is sent on the 201 port for the fragmentation package.
I can't find it in the Lora fragmented block transport specification or anywhere else

[mluis1]

This request was part of the original non public LoRa-Alliance test specification.
This was used to verify that the downloaded binary file was correct.