NN was formerly part of the German Empire. In the German Empire, the place was called NN.
The place is now called Bolków and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Bolkow A | Russian Empire | Veljunˈ | 1914 |
| Bolkow B | Russian Empire | Veljunˈ | 1914 |
| Bolków A | Poland | Wieluń | 1921 |
| Bolków B | Poland | Wieluń | 1921 |
| NN | German Empire | Welungen | 1939 |
| Bolków (A i B) | Poland | Wieluń | 1945 |
| Bolków | Poland | Sieradz | 1992 |