what does “Left rr tire low add air to tire ” mean?

I know its telling me add air but I already added to spesifications and I am not sure what does “rr” mean..

Rr could mean rear. Because tire pressure varies with temperature, try making the tires all the same rather than trying to make the one match specifications. That way if you have a bad sensor you will still be safe.

Left ReaR tire

After putting air in, you have to sincronize all the wheel sensors. Look in your maint book or take to a tire shop

It means you are too stupid to own or drive a car.