This was initially issued by the Soviet Military Administration in Germany (SMAD), then from 1951 by the Office for Literature and Publishing (Main Administration for Publishers and Book Trade) and, after its integration into the Ministry of Culture, by the Ministry.
[1] Independently of this, each edition of a book had to be individually licensed as part of the so-called printing approval process.
In those books, the specific printing approval number usually had to be stated in the imprint (see e.g. TGL 24464[2]).
The printing permit procedure and thus the regulations for specifying the license numbers in the books lasted until December 1, 1989.
However, they could sometimes change over time - e.g. in connection with restructuring, mergers and spin-offs of publishing houses.