GSCO (Global Standard Classification of Occupations) is a deterministic multilingual database that aggregates 129 national occupation classifiers into a single ISCO-08-aligned structure to expose and resolve cross-table incoherence. The paper documents the methodology, audits 22 common professions across all 9 ISCO major groups, and demonstrates concrete cases where national taxonomies diverge irreconcilably from ISCO-08 — including renumbered major groups (South Africa OFO 2017), parser-truncation bugs (Brunei BDSOC), and absent occupations (Togo zemidjan moto-taxi, Honduras moto-taxi forestal, Guatemala bicitaxis). Includes worked examples for ISCO 2221 (nurses vs financial brokers vs medical doctors), the universal teacher/taxi-driver case, and recommendations for the ILO's ISCO-28 working group (active revision phase 2026–2028). Open dataset and per-country reports at
gsco.io. Repository:
github.com