Tajná was formerly part of the German Empire. In the German Empire, the place was called Tajná.
The place is now called Tajná and belongs to Czech Republic.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Thein | Austro-Hungary | Melnik | before the Treaty of Saint-Germain |
| Tejno | Austro-Hungary | Melnik | before the Treaty of Saint-Germain |
| Tajná | Austro-Hungary | Melnik | before the Treaty of Saint-Germain |
| Tajná | Czechoslovakia | Mělník | after the Treaty of Saint-Germain |
| Tein | German Empire | Melnik | 1939 |
| Tajná | German Empire | Melnik | 1939 |
| Tajná | Czechoslovakia | Mělník | 1945 |
| Tajná | Czechoslovakia | Mělník | 1992 |
| Tajná | Czech Republic | Mělník | 1993 |