The SB, or Służba Bezpieczeństwa (Security Service), was the agency identified in declassified documents^[1] as the operator of the Swedish Rhapsody family of numbers stations including G02 and M04. In 1990, after the fall of communism, the SB was replaced by the UOP, or Urząd Ochrony Państwa (Office for State Protection).

In 1998, G02 was succeeded by E23. In 2002, the UOP was split into two separate agencies: ABW, Agencja Bezpieczeństwa Wewnętrznego (Internal Security Agency), and AW, Agencja Wywiadu (Foreign Intelligence Agency). E23 operations lasted from 1998 to 2007, so it seems likely that the agency that carried them on following the split of the UOP was one of these two successors.

National Holidays in Poland

References

1. Numbers & Oddities #200 (May 2014) [accessed March 10th, 2018]