Common Operational Datasets

Code assignment

Codes are numbered in a fixed sort order within each parent, never renumbered and never reused. The source's own codes are kept alongside.

First draft reviewed by UN80 Data QuintJuly 2026

Code assignment

The procedure when P-codes are assigned to a country is as follows. Within each parent, sort all units by adm[N]_srcid, then adm[N]_name, then adm[N]_name1, then adm[N]_name2, then adm[N]_name3 (nulls sort last at each step), and assign sequential integers in that order, starting at 001, resetting per parent.

For updates this same cascade, sort by adm[N]_srcid, then adm[N]_name, then adm[N]_name1–name3, governs every subsequent code assignment as well: when units are added under an existing parent, they are sorted using this cascade and assigned the next available sequential integers in that resulting order. Units that already hold a P-code are never re-sorted or renumbered. The number carries no meaning beyond “this is the Nth unit registered under this parent.” P-codes are never reused: no existing or historic code can be assigned to a new unit.

Source codes

Previously, COD-AB P-codes were derived from national government coding systems. When a government changed its own codes, every OCHA dataset built on those codes required full re-keying, breaking all downstream joins.

P-codes are now assigned independently using a consistent format. The originating source ID (whether from a national government, WFP, or another authoritative system) is preserved in the level-specific source fields (adm1_srcid, adm2_srcid, etc.), enabling downstream users to join data back to whichever source system they work with. The P-code remains stable regardless of what any source system does with its own codes.

The default source is the national government’s own coding system. Where a government code is not available, a third-party source (WFP, GADM, OSM, or another authoritative system) is accepted instead. adm[N]_srcid is populated from whichever dataset supplies the code key for that unit at that version, government by default, third-party where no government code exists.