Methodology
How data is imported, checked, merged and displayed on the site.
Import and source priority
Imports prioritize official national sources, then reliable European datasets, then complementary datasets when they fill a gap. Each source keeps its own licence, update date and precision limits.
Merging duplicates
Rows are grouped by country, locality and postcode. When several rows represent the same relation, the site keeps one canonical page and merges useful details such as region, municipality, coordinates and source metadata.
Main postcodes
For towns with several postcodes, the display favors ordinary geographic postcodes over special or administrative codes. Associated postcodes remain visible from the town page.
Nearby towns
Nearby towns are calculated only when coordinates are reliable enough. Distance uses geographic coordinates first; when coordinates are missing, the fallback relies on the same administrative area or postcode prefix.