Original sentence: It was founded on 1 June 1922 out of the Royal Irish Constabulary (RIC), the Belfast Borough Police Force and the Londonderry Borough Police Force (also known as the "Derry City Force")
Edited sentence: It was founded on 1 June 1922 out of the Royal Irish Constabulary (RIC), the Belfast Borough Police Force and the Londonderry Borough Police Force (known colloquially as the "Derry City Force" - a name which stayed for many years)