instrument vs opinion

Other hyponyms of instrument include articles of incorporation, derivative, derivative instrument, negotiable instrument, passport, ship's papers, manifest, debenture, power of attorney, letters of administration, letters testamentary, work papers, work permit, working papers, act, enactment, law, bill, measure, brief, legal brief, testament, will, living will, deed, deed of conveyance, title, assignment, deed of trust, trust deed, conveyance, income tax return, return, tax return, licence, license, permit, letters patent, patent, judgement, judgment, legal opinion, acquittance, release, judicial writ, writ, authorisation, authorization, mandate, affidavit, written agreement, bill of indictment, indictment, impeachment, arraignment, certificate, security.