"Neuk" is the Scots word for nook or corner, and the East Neuk is generally accepted to comprise the fishing villages of the most northerly part of the Firth of Forth and the land and villages slightly inland therefrom. In effect, that part to the south of a line drawn parallel to the coast from just north of Earlsferry to just north of Crail. As such it would include Earlsferry, Elie, Colinsburgh, St Monans, Pittenweem, Arncroach, Carnbee, Anstruther, Cellardyke, Kilrenny, Crail and Kingsbarns. The boundaries set by local government are the old wards. This means according to this method that Lundin Links to Crail are part of the East Neuk.
However, there is a cachet to being part of the East Neuk, and other villages have laid claim to the address, particularly Lundin Links, Upper Largo and Lower Largo. Some disquiet was evident in the fishing villages when a sign was erected outside Lundin Links proclaiming that the passer was entering the East Neuk of Fife.
Until someone can find indisputable historic reference to the area enclosed or Local Government intervenes it is unlikely that membership can be resolved.