The binding principles established are: (1) For purposes of s 2(1)(b) of the Vexatious Proceedings Act, 'legal proceedings' means only proceedings in courts (High Court, Supreme Court of Appeal, Constitutional Court, Labour Court and similar status courts) and lower courts (magistrates' courts, regional courts), not administrative tribunals or quasi-judicial bodies. Bargaining councils established under the LRA are administrative tribunals, not courts. (2) 'Persistent' in s 2(1)(b) means recurring, constantly repeated or continuous institution of legal proceedings - not merely multiple unsuccessful attempts by a self-represented litigant to identify the correct forum for different causes of action. (3) 'Without reasonable grounds' requires a clear showing that claims have no basis - this cannot be established where claims were not decided on merits. (4) Applicants seeking vexatious proceedings orders must first rely on the Vexatious Proceedings Act, not directly invoke s 173 of the Constitution, which codifies but does not replace the statutory framework. (5) Under common law principles (now in s 173), proceedings are vexatious only if 'obviously unsustainable as a certainty', not on a preponderance of probability. (6) Given the limitation on the constitutional right of access to courts, the Vexatious Proceedings Act must be narrowly construed and courts must proceed very cautiously, only in clear cases, and craft orders to meet only immediate requirements. (7) A respondent seeking to cross-appeal must obtain leave to cross-appeal in terms of Uniform Rule 16(1)(a); failure to do so renders the cross-appeal incurably flawed.