Methodology
Aggregation and normalisation of public postal and geographic data, with every value traceable to its source.
Principle
CodePostalPro aggregates publicly available postal and geographic information (postal operators, open datasets, collaborative databases), normalises it into a common model — country › administrative region › delegation or post office › locality — and publishes it with its source and a verification status. We never create postal codes: when a value cannot be established, the page says so explicitly.
Normalisation
- Names: sources are often in unaccented capitals. We restore accents for a controlled vocabulary of common French nouns (Cité, Résidence, École, Aéroport…) and keep the original spelling on the page when it differs.
- URL identifiers: lower-case, no diacritics, words separated by hyphens, apostrophes removed. Historical French URLs (2015–2023) redirect one-to-one to their French page under
/fr/. - Hierarchy: Tunisia — governorate › delegation › locality; Algeria — wilaya › post office › locality (one post office corresponds to one postal code and serves one or more localities).
- Coordinates: taken from the source with its precision level (postal-area centroid, locality…). They power the “nearby localities” lists.
Verification statuses
- Concordant sources — the same value appears in at least two independent sources.
- Single source — value from one source, not cross-checked.
- Conflicting sources — sources give different values; the page shows all of them with their origin.
- Unverified — no usable source; the page only carries geographic information.
Pages without sufficient information are excluded from search engines (noindex) until improved.
Tunisia
Hierarchy and codes follow La Poste Tunisienne’s lookup service (governorate › delegation › locality), via a structured community transcription, cross-checked with a second dataset (Arabic names, coordinates and main code of each delegation). The 17 delegations and localities of Tunis, Bizerte and Jendouba still referenced by Wikipedia were checked individually: the main code of each delegation agrees in both datasets. Direct verification on poste.tn, unreachable from our environment at build time, will be repeated.
Algeria
Place names, wilayas, post-office groupings and coordinates come from GeoNames (CC BY 4.0). Caution: Algeria renumbered its postal codes in 2008; the numbering found in GeoNames differs, for a large share of post offices, from the post-2008 list compiled from Algérie Poste (e.g. Hydra: 16016 in GeoNames, 16035 in the 2008 list). We could not consult Algérie Poste’s website directly (connection refused, no archive available). Consequently:
- the GeoNames value is shown as the primary value, with its source;
- when Wikidata or the Wikipedia list give another value for the same locality, it is shown alongside (“Other recorded value”) and the page gets the “Conflicting sources” status;
- a value is only called “concordant” when two independent sources give it.
Algérie Poste’s official list will be integrated as the reference source as soon as it can be consulted; affected pages will be updated and the history of values kept.
Limits
- Postal codes and administrative boundaries change; a page reflects the generation date shown at its bottom.
- Sources may contain typing errors, duplicates or obsolete names.
- Postal operators (La Poste Tunisienne, Algérie Poste) remain the sole authority.
Corrections
Every page has a “Report an error” link. Give the page address, the expected value and, if possible, a verifiable source (postal operator’s website, official document). Open the form.