I'm reading Brigitte Reimann's "Die Geschwister" (a story about two siblings living in the DDR, one of them planning to flee to BRD) and the author constantly uses two abbreviations "R." and "D.", for example:
Sie lachten: Zeig uns mal dein Wunder von einem Bruder. Uli studierte aber zu der Zeit in R., an der Ostseeküste, und ich besuchte die Kunsthochschule in D., und dazwischen lagen fünfhunder Kilometer Eisenbahnstrecke. [2007 edition, page 7]
There are many other mentions to both throughout the book.
Unless missed some earlier reference for what R. and D. refer to, those are used as some sort of universal abbreviations.
Being one-letters "words", these are difficult to find on dictionaries.
Given the thema and context, I'm inferring they refer to DDR and BRD.
What do they mean? What actual words to they stand for?