Lodges and Grand Lodges whose charters' roots derive from the United Grand Lodge of Ancient Freemasons of England , The Grand Lodge of Ireland or the Grand Lodge of Ancient Free and Accepted Masons of Scotland use the expression, A∴F∴& A∴M∴
Those Grand Lodges that don't use the appellation "Ancient", claim descent from the "Grand Lodge of Free and Accepted Masons under the constitution of England" during the period from 1717 until 1813.
This English Grand Lodge was constituted from four lodges on June 24, 1717. A later Grand Lodge in England, styling themselves Ancient, labelled the first group "Modern" although today the preferred term is "Premier." The "Moderns" and "Ancients" united in November 25, 1813 to form the United Grand Lodge of Ancient Freemasons of England [now styled the United Grand Lodge of Ancient Free and Accepted Masons of England].
The choice of style is not universal as some Grand Lodges simply chose one or other title for reasons of their own. The usage has no bearing on regularity or recognition.
