Categories and Sectors - How Systems Are Organized
TL;DR: 1,000+ classification systems are organized into 16 categories spanning industry, trade, health, occupation, regulation, and domain-specific vocabularies. This guide explains the category structure and how to navigate it.
The 16 categories
graph TD
WOT["WorldOfTaxonomy\n1,000+ systems"] --> IND["Industry\n~150 systems"]
WOT --> TRADE["Product/Trade\n~20 systems"]
WOT --> OCC["Occupation\n~15 systems"]
WOT --> EDU["Education\n~10 systems"]
WOT --> LIFE["Life Sciences\n~100+ systems"]
WOT --> GEO["Geographic\n~10 systems"]
WOT --> FIN["Financial/Environmental\n~20 systems"]
WOT --> REG["Regulatory\n~100+ systems"]
WOT --> ISO["ISO Standards\n~25 systems"]
WOT --> INTL["Intl Agreements\n~25 systems"]
WOT --> ACAD["Academic\n~15 systems"]
WOT --> PAT["Patent\n1 system, 254K codes"]
WOT --> DTECH["Domain: Technology\n~50 systems"]
WOT --> DFIN["Domain: Finance\n~30 systems"]
WOT --> DSEC["Domain: Sector-Specific\n~200+ systems"]
WOT --> DREG["Domain: Regulatory Detail\n~50+ systems"]
| Category | Systems | Description |
|---|---|---|
| Industry | ~150+ | Economic activity classification (NAICS, ISIC, NACE, SIC, national variants) |
| Product/Trade | ~20+ | Goods and services classification (HS, CPC, UNSPSC, SITC) |
| Occupation | ~15+ | Job and skills classification (SOC, ISCO, ESCO, O*NET) |
| Education | ~10+ | Educational programs and levels (ISCED, CIP) |
| Life Sciences | ~100+ | Pharmaceuticals, clinical coding, diagnostics, devices, biotech, health informatics |
| Geographic | ~10+ | Country, region, and subdivision codes (ISO 3166, NUTS, FIPS) |
| Financial/Environmental | ~20+ | Sustainability, accounting, and governance (SASB, EU Taxonomy, GHG, COFOG) |
| Regulatory | ~100+ | Laws, standards, and compliance frameworks (HIPAA, GDPR, OSHA, FDA, SEC) |
| ISO Standards | ~25+ | Management system standards (ISO 9001, 14001, 27001, 45001) |
| International Agreements | ~25+ | Treaties and global frameworks (Basel, FATF, Paris Agreement, ILO) |
| Academic/Research | ~15+ | Subject classification for scholarly work (arXiv, MSC, JEL, ACM CCS) |
| Patent | 1 | Patent classification (CPC - 254K codes) |
| Domain: Technology | ~50+ | Software, AI, cybersecurity, cloud, data taxonomies |
| Domain: Finance | ~30+ | Insurance, banking, investment, payment taxonomies |
| Domain: Sector-Specific | ~200+ | Transportation, agriculture, mining, construction, energy, and other sector vocabularies |
Category counts in the knowledge graph
graph LR
subgraph By_Nodes["Distribution by Node Count"]
NCI_L["Life Sciences\n568K+ nodes"]
PAT_L["Patent CPC\n254K nodes"]
TRADE_L["Product/Trade\n100K+ nodes"]
IND_L["Industry\n50K+ nodes"]
OCC_L["Occupation/Skills\n40K+ nodes"]
DOM_L["Domain Vocabularies\n10K+ nodes"]
end
| Category | Systems | Nodes | What drives the count |
|---|---|---|---|
| Life Sciences | ~100+ | 568K+ | ICD-10-CM (97K), NCI Thesaurus (211K), NDC (112K), LOINC (102K) |
| Patent | 1 | 254K | Patent CPC is a single massive hierarchy |
| Product/Trade | ~20 | 100K+ | UNSPSC dominates with 77K codes |
| Industry | ~150+ | 50K+ | Many national NACE/ISIC variants at ~1K codes each |
| Occupation/Skills | ~15 | 40K+ | ESCO Skills at 14K, ESCO Occupations at 3K |
| Domain vocabularies | ~300+ | 10K+ | Typically 15-30 codes each |
| Regulatory/Compliance | ~100+ | 5K+ | Frameworks range from 15-50 articles each |
| Everything else | ~300 | 15K+ | Geographic, academic, financial, ISO |
How categories map to API queries
Browse by category
# Get all systems (includes category metadata)
curl https://worldoftaxonomy.com/api/v1/systems
# Group by region
curl "https://worldoftaxonomy.com/api/v1/systems?group_by=region"
# Filter by country to find relevant systems
curl "https://worldoftaxonomy.com/api/v1/systems?country=US"
Search within a category
The search endpoint searches across all systems. Use keywords to focus on specific domains:
# Find health-related codes
curl "https://worldoftaxonomy.com/api/v1/search?q=diabetes&grouped=true"
# Find trade codes
curl "https://worldoftaxonomy.com/api/v1/search?q=cotton&grouped=true"
# Find occupation codes
curl "https://worldoftaxonomy.com/api/v1/search?q=software+engineer&grouped=true"
Domain-specific vocabularies
Domain taxonomies extend the standard classification systems with specialized vocabularies. They are organized by NAICS 2-digit sector.
Sector-specific domains
| NAICS Sector | Domain Vocabularies | Total Codes |
|---|---|---|
| 11 Agriculture | Crop types, livestock, farming methods, commodity grades, equipment, input supply, land classification, post-harvest | 300+ |
| 21 Mining | Mineral types, extraction methods, reserve classification, equipment, project lifecycle, safety | 130+ |
| 22 Utilities | Energy sources, grid regions, tariff structures, infrastructure assets, regulatory ownership | 130+ |
| 23 Construction | Trade types, building types, project delivery, material systems, sustainability | 130+ |
| 31-33 Manufacturing | Process types, quality, operations models, industry verticals, supply chain, facility config | 120+ |
| 44-45 Retail | Channel types, merchandise categories, fulfillment, pricing strategies, store formats | 100+ |
| 52 Finance | Instrument types, market structure, regulatory frameworks, client segments | 100+ |
| 484 Truck Transportation | Freight types, vehicle classes, cargo, carrier operations, pricing, compliance | 200+ |
Emerging sector domains
| Domain | Focus | Systems |
|---|---|---|
| AI and Data | Model types, deployment, ethics, governance | 4 |
| Cybersecurity | Threats, frameworks, zero trust, SIEM | 10+ |
| Space and Satellite | Orbital classification, regulatory, licensing | 4 |
| Climate Technology | Finance instruments, policy mechanisms | 4 |
| Quantum Computing | Application domains, commercialization stages | 4 |
| Digital Assets/Web3 | Regulatory frameworks, infrastructure layers | 4 |
| Autonomous Systems | Application domains, sensing technology | 4 |
| Synthetic Biology | Application sectors, biosafety levels | 4 |
Life Sciences sub-sectors
The Life Sciences category (~100+ systems, ~568K nodes) is the largest by node count. It is organized into 13 sub-sectors:
| Sub-Sector | Key Systems |
|---|---|
| Diagnoses and Classification | ICD-10-CM, ICD-11, ICD-10-PCS, DSM-5, SNOMED CT, ICPC-2 |
| Pharmaceuticals | ATC, NDC, RxNorm, EDQM, WHO Essential Medicines |
| Diagnostics and Lab | LOINC, lab test types, imaging modalities, biomarkers |
| Procedures and Billing | CPT, HCPCS, MS-DRG, G-DRG, NUCC |
| Oncology and Research | NCI Thesaurus, MeSH, OMIM, Orphanet, CTCAE |
| Medical Devices | GMDN, implant types, surgical instruments, sterilization |
| Biotechnology | Biotech types, biosimilars, gene therapy, cell therapy |
| Synthetic Biology | Synbio types, application sectors, biosafety levels |
| Health Informatics | FHIR, DICOM, telemedicine, clinical decision support |
| Nursing and Allied Health | ICN, NIC, NANDA, nursing specialties, allied health |
| Payment and Delivery | HEDIS, CMS Star, care settings, payer types, value-based care |
| Health Regulation | HIPAA, FDA 21 CFR, DEA, CLIA, MDR, IVDR |
| Dental, Mental, and Veterinary | Dental, mental health, and veterinary service types |
Navigating categories
Use the web app at worldoftaxonomy.com for visual exploration. The home page Industry Map shows all 16 categories. Click any category to search for systems in that domain.
Use the API for programmatic access:
# Get all systems with metadata
curl https://worldoftaxonomy.com/api/v1/systems
# Get country-specific systems (e.g., what applies in Germany)
curl "https://worldoftaxonomy.com/api/v1/systems?country=DE"
# Get crosswalk statistics to see which systems are most connected
curl https://worldoftaxonomy.com/api/v1/equivalences/stats