Gas gauge on '73 VW

What does “R” mean on gas gauge of 1973 Volkswagen campmobile (Kombi van)? My husband initially said it meant “reserve,” but then later admitted he made that up. It seems to either mean “quarter tank” or “empty,” but it would be cool to know for sure. Thanks!

I am going to go with reserve, empty would be “leer” if I remember my German.

reserve,i think.my dad had a '75 super beetle when i was a kid.when my brother would drive it he would frequently run it almost empty,and i would have to open the glove box and throw a lever to switch to the reserve tank(it was about 1~1.5gal)that’s what i remember,not sure if my brain is tricking me or not.

It is indeed reserve. It means (assuming the gas gauge is still accurate) that you’ve got about 1 gallon left. Here’s the owner’s manual:

http://www.thesamba.com/vw/archives/manuals/72bus.php