CM

Cameroonian AFA Codes, officially incorporated as BANOC - Base d'Adresses Numérique Ouverte du Cameroun.

This repository serves as the "public part" of the AFAcodes_gridGen-CM configurations.
The source code for the software AFAcodes_gridGen-CM will be generated here (under a src folder) by AFAcodes-softwareGen — the software generator system which generates the "AFA Codes System" software for specific countries. Both pieces of software are registered with INPI.

The data-CC0 folder contains CC0-licensed data. The data-licensed folder contains data with other Creative Commons license.

When the src folder is present, the licenses and instructions in that folder must be followed.

Canonical URL for this repository: git.AFA.codes/CM

Nominal geocodes of CM

Cameroon is assigned the following geocodes: in the ISO 3166 context, the 2-letter abbreviation-code CM and the numeric code 120. Other considered geocodes: in Wikidata, the identifier is Q1009; in OpenStreetMap, the relation ID is 192830.

For administrative purposes, the national territory and its subdivisions represent jurisdictions:

• The country is divided into 10 regions (formerly provinces). The geocodes for these regions follow the convention registered by ISO 3166‑2:CM. In OpenStreetMap, the regions correspond to administrative level 4.

• The regions are further subdivided into departments, communes (arrondissements), and districts. There are a total of 360 subdivisions, which are ISO 3166‑2:CM's third-level subdivisions.
  These are listed as official "extended ISO labels" in data-restricted/citycover.csv (column isolabel_ext), forming a hierarchical naming geocode system under the syntax CM-$L2-$L3.
  Codes in the form CM-$L2 represent the provinces, and $L3 are expressed as CamelCase ASCII transcriptions of complete names without accents or separators. Examples: CM-SU-KyeOssi for Kyé-Ossi, CM-CE-Soa for Soa, CM-SU-Maan for Ma'an.

Grid-system geocodes

Geocodes based on regular hierarchical grids can be encoded and decoded from latitude-longitude coordinates. They adhere to the DNGS standard - Discrete National Grid Systems, a variation of the ISO DGGS standard designed for national rather than global requirements.

Grid AFA Codes follow the DNGS standard. For Cameroon, they are defined in the dngs_definition parameter in the conf.yaml configuration file. The grid system uses a refinement ratio of 2, subdividing parent cells into child cells. It starts with 16 squares, each 262.144 km on a side, covering Cameroon’s territory, as illustrated below. As "power of 2" codes, they are expressed using hexadecimal-like codes (base 16h representation).

Long grid-based geocodes, for example 915a69ddS, an address-point of 32 m², are difficult to transcribe or memorize by humans. It can be shortened by context. DNGS suggests using nominal geocodes as context and, for human readability, adopts the compact base 32 representation. The resulting notation (in the example CM-SOA~B6MRD), called "logistic geocode", is defined in the files citycover.csv, citycover_dust.csv, and citycover_dustDEL.csv in the data-restricted folder.

Extended Geo URI

All "official geocodes" can be used with the Extended Geo URI protocol (described on page 140 here).