Plajnsko was formerly part of the German Empire. In the German Empire, the place was called Kreuzdorf.
The place is now called NN and belongs to Slovenia.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Plainsko | Austro-Hungary | Pettau/Ptuj | before the Treaty of Saint-Germain |
| Planjsko | Austro-Hungary | Pettau/Ptuj | before the Treaty of Saint-Germain |
| Plajnsko | Yugoslavia | Ptuj | after the Treaty of Saint-Germain |
| Kreuzdorf | German Empire | Pettau | 1941 |
| Planjsko | Yugoslavia | Ptuj | 1945 |
| Planjsko | Yugoslavia | Socialistična rep. Slovenija | 1992 |
| NN | Slovenia | Slowenien | 1991 |