Do you sometimes wonder what the letters above the Rollei name mean?
All of these letters have to do with German Patents and Trademarks.
DBP is: Deutsches Bundes Patent.
DRP is: Deutsches Reichs Patent.
DBGM is: Deutsches Bundes Gebrauchs Musterschutz
DRGM is: Deutsches Reichs Gebrauchs Musterschutz
I do not speak or understand German, but I think you get the general meaning. They simply mean that patents have been obtained for the camera. And the others are Rollei Trademarks.
Hope this helps!