Protocol 15 introduces important changes to the Convention system. These changes, in brief
– add a reference to the principle of subsidiarity and the doctrine of the margin of appreciation to the Preamble of the Convention;
– shorten from six to four months the time limit within which an application must be made to the Court;
– amend the ‘significant disadvantage’ admissibility criterion to remove the second safeguard preventing rejection of an application that has not been duly considered by a domestic tribunal;
– remove the right of the parties to a case to object to relinquishment of jurisdiction over it by a Chamber in favour of the Grand Chamber; and
– replace the upper age limit for judges by a requirement that candidates for the post of judge be less than 65 years of age at the date by which the list of candidates has been requested by the Parliamentary Assembly.
The Explanatory Report and the Opinion of the Court on Protocol 15 can be found here and here.