The HRA 1998, s 6(3)(a) recognises that courts and tribunals are 'core public authorities'. This suggests that their judgments and orders must be compatible with Convention rights, even in proceedings between private parties, allowing Convention rights to affect the substance of private law by virtue of the court's duty, owed to litigants, not to act incompatibly with their rights. This effect between private parties is referred to as the indirect 'horizontal effect' of the HRA 1998 (as distinct from the 'vertical effect' between a private individual and a state body).