Companies House company_type values to include. Empty = all supported incorporated types: ltd, plc, llp, private-unlimited, private-unlimited-nsc, private-limited-guarant-nsc, private-limited-guarant-nsc-limited-exemption, private-limited-shares-section-30-exemption, old-public-company, european-public-limited-liability-company-se, charitable-incorporated-organisation, scottish-charitable-incorporated-organisation, industrial-and-provident-society, registered-society-non-jurisdictional, royal-charter, assurance-company, protected-cell-company, investment-company-with-variable-capital, icvc-securities, icvc-warrant, icvc-umbrella, further-education-or-sixth-form-college-corporation. Partnerships, overseas entities and other types are never included.