NN (Pertoltice) was formerly part of the German Empire. In the German Empire, the place was called NN.
The place is now called Pertoltice and belongs to Czech Republic.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| NN (Pertoltice) | Austro-Hungary | Friedland (Isergebirge) | before the Treaty of Saint-Germain |
| NN | Czechoslovakia | Frýdlant | after the Treaty of Saint-Germain |
| NN | German Empire | Friedland (Isergebirge) | 1938 |
| NN | Czechoslovakia | Frýdlant | 1945 |
| Pertoltice | Czechoslovakia | Liberec | 1992 |
| Pertoltice | Czech Republic | Liberec | 1993 |