History and specifics
Cynur IV was a member of the Federation and was connected to its interstellar databases. The world often hosted festivals.
In 2267, a computer virus hidden in an update to Federation-wide databases erased all the planet's historical and medical records, along with those of many other worlds. The starship USS Enterprise visited Cynur IV and assisted the Cynurians in rebuilding their electronic records, and did likewise on Emben III and Tyrtaeus II. (TOS novel: Heart of the Sun)