This is a binary CSV format. Incredibly simple, and separated by ASCII Control characters. This uses SOH (Start of Heading), STX (Start of Text), ETX (End of Text), ESC (Escape), US (Unit Separator), and RS (Record Separator).
The stream is expressed in the following faux-EBNF (where * represents any single byte):
ebnf
stream = [header], STX, records, ETX
header = SOH, units
units = unit, { US, unit}
unit = { (* - control) | (ESC, *) }
control = SOH | STX | ETX | ESC | US | RS
records = units, { RS, units}