Know your data sources.

Pan-EU harmonized offshore oil & gas — OGC WFS 2.0.0, no auth. 18 EU countries (Croatia, Cyprus, Denmark, Faroe Islands, France, Germany, Greece, Ireland, Italy, Latvia, Malta, Montenegro, Netherlands, Norway, Poland, Portugal, Spain, UK). Annual refresh — breadth filler; prefer sodir/nsta for authoritative national data. Layers: - hydrocarbons (~28.5K wells) ⭐ status/purpose/content/country filters - platforms (~1.6K) ⭐ currentStatus/category/primaryProduction - pipelines (~3.9K) ⭐ medium/status/country - activelicenses (~1.3K polygons) type/country

USGS MRDS + USMIN — global mineral deposits + US mine-feature points (no auth). Upstream (MapServer WFS 2.0.0): - /services/wfs/mrds — ms:mrds (~304K worldwide deposits) - /services/wfs/usmin — ms:points + ms:polygons (US only) Rich per-record JSON: /mrds/json/{dep_id} returns 26+ subtables (commodities, materials, ages, ore body, production, references, rocks). Filters: commodity (CU/AU/AG/FE/LI/U/REE/PGE…), country (FIPS), US state, dev_stat (Past Producer/Producer/Occurrence/Prospect/Plant/Raw Prospect), bbox. §0 quirks: CQL_FILTER silently ignored by MapServer — handler emits OGC FILTER= XML (fes:Filter). fips_code stored with literal "f" prefix (fCI / f06065). code_list space-separated with leading space.