The schematic and some parts define which side of the car is defined as left hand (sitting in the car looking out the front). This is done rather than saying drivers side or passenger side because those sides can change if the cars are made for another country.

I was looking at my Zilla schematic so I could add wire colors to my installation document for my side light flasher board.

Well looks like the Zilla schematic is messed up. Fuse #2 powers the LH (our drivers side) front marker and side marker labeled LH and powers the rear drivers side tail light, left license plate, and side marker labeled RH. So the labels fro the rear lights are swapped.

I have not looked at other schematics.