nacsand n;
You are seeing one of the HELP prompts. These are a series of prompts that may appear on the Meter Panel Display if a function, such as lift or traction, is being interlocked. The prompt will only appear as the function is being operated and will only cover the basic interlock of the truck.
The prompts that come close to the one you are showing are:
L,boot - The Lift controller failed it's power on self test or
the battery is flat
T,boot - The Traction controller failed it's power on self test
L,Foot - On a single pedal truck, the left foot switch isn't
operated