NN was formerly part of the German Empire. In the German Empire, the place was called Koschlau.
The place is now called NN and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| NN (Koschlau) | German Empire | Neidenburg | before the Versailles Treaty |
| NN | Poland | Działdowo | after the Versailles Treaty |
| Koschlau | German Empire | Neidenburg | 1939 |
| NN | Poland | Działdowo | 1945 |
| NN | Poland | Ciechanów | 1992 |