Dekmanca was formerly part of the German Empire. In the German Empire, the place was called NN.
The place is now called Dekmanca and belongs to Slovenia.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Deckmannsdorf | Austro-Hungary | Rann/Brežice | before the Treaty of Saint-Germain |
| Dekmanca | Austro-Hungary | Rann/Brežice | before the Treaty of Saint-Germain |
| Dekmanca | Yugoslavia | Šmarje | after the Treaty of Saint-Germain |
| NN | German Empire | Rann | 1941 |
| Dekmanca | Yugoslavia | Celje | 1945 |
| Dekmanca | Yugoslavia | Socialistična rep. Slovenija | 1992 |
| Dekmanca | Slovenia | Slowenien | 1991 |