The UK's highest court gives a ruling today in the latest round of a legal battle over how police in the North handled the union flag protests.
In April 2014, a High Court judge ruled in favour of a resident of the nationalist Short Strand area of east Belfast, who claimed the police's failure to stop unnotified loyalist marches past his home between December 2012 and February 2013 breached his right to privacy and family life.
But, later that year, appeal judges overturned the ruling following a challenge by the PSNI.
Five Supreme Court justices in London are to announce their decision on an appeal by the resident, who challenges the policing strategy.
Mass loyalist demonstrations, some of which descended into serious violence, were staged across Northern Ireland in opposition to Belfast City Council's decision to limit the number of days the union flag flew over City Hall.
As permission for the loyalist marches was not sought from the Parades Commission adjudication body, the events were not lawful.
In finding in favour of the unnamed resident, the judge at the High Court in Belfast found that police had not properly understood their powers to intervene in the protests.
But three appeal judges, among them Northern Ireland's Lord Chief Justice Sir Declan Morgan, came to a different conclusion and allowed the PSNI's appeal against the judgment.
The PSNI had argued that the original ruling regarding its handling of union flag protests would have placed major constraints on how it polices future parades and demonstrations in the North.
They said commanders' decisions to contain the protests and pursue arrests and charges at a later date fell within their discretionary powers.
One of the issues Supreme Court president Lord Neuberger and the other justices will be deciding is "whether the Police Service of Northern Ireland misdirected itself as to the extent of its legal powers to stop illegal parades".
The second is "the appropriate standard of review and scope of discretion to be afforded to the police in making operational decisions concerning public order issues".