OK, let's break it down:
R2 OB SC LF PT ET

R2 - He's on this flight, we R 2
OB - O B still and please don't make any requests of us
SC - This, and all pax, are considered Self-loading Cargo
LF - Prefers seating on the LeFt side of the aircraft
PT - This pax is Potty Trained
ET - He also appears Extra Terrestrial, may need to call home;
an alternate meaning is This passenger has Exit Trauma

Dang, I've learned things good on FT!