Protocol No. 15 amended the preamble of the European Convention on Human Rights (the Convention) to include a reference to the principle of subsidiarity and the margin of appreciation doctrine. It also changed other provisions of the Convention, notably certain aspects of the criteria on the admissibility of an application by the European Court of Human Rights (the Court).

Protocol No. 16 enabled the highest courts and tribunals of a State Party to request the Court to give an advisory opinion on questions of principle relating to the interpretation or application of the rights and freedoms defined in the Convention or the Protocols thereto.

Protocols No. 15 and No. 16 represent key steps of the reform process of the Court and the system of the Convention. Evaluating their impact contributes to the ongoing intergovernmental work on the implementation of the Convention at the national level.

In the framework of its mandate for the period 2024–2027, the Steering Committee for Human Rights (CDDH) created, at its 99^th meeting (28 November–1 December 2023) the Drafting Group on the evaluation of the first effects of Protocols No. 15 and No. 16 to the European Convention on Human Rights (DH-SYSC-PRO). Its member States are Armenia, Azerbaijan, Belgium, Czechia, Finland, Ireland, Montenegro, Netherlands, Poland and Spain.

The CDDH is expected to consider draft reports prepared by the Group on Protocols No. 15 and No. 16 respectively by December and June 2025.