Serial output undocumented

I see serial output (from an RFM2Pi but ISTR that I get something almost identical from the unit itself) looking something like this:

OK 8 146 21 11 0 28 0 0 0 65 93 184 11 184 11 184 11 184 11 184 11 184 11 0 0 0 0 (-69) 

I'm fairly sure this used to be documented, but it seems to be unmentioned in the current documentation.

Update: I managed to work it out using my own code at https://github.com/merbanan/rtl_433/blob/master/src/devices/emontx.c#L116

Would still be good if this was easier to find in the documentation.