# Is the municipality BfS Nr. unique over time?

#### 19.05.2024

No.

# Example

The bfs_nr 3955 belongs to the municipalitiy Landquart (GR). Until October 1977, this bfs_nr 3955 was also in use but for different geographical entity, namely the “Gemeindefreies Gebiet Maienfeld-Fläsch”.

# Consequence

To join two datasets of two different time periods, one might think that the bfs_nr can be used to do the join. However, this is not possible because the bfs_nr can be reattributed over time. Thus, a simple bfs_nr based join is not possible.