Until 1963-04-30, the all the islands of the Channel Islands counted for a single DXCC entity, Channel Islands.
In the March, 1963 issue of QST, ARRL announced that the single entity of Channel Islands would be dropped, and replaced by two entities, Guernsey & Dependencies and Jersey.
This change was not considered a deletion. Credits which had already been made for Channel Islands were automatically credited to Guernsey or Jersey upon presentation of the appropriate confirmation.
Until 1976-12-31, the prefix for Channel Islands/Guernsey/Jersey was GC. Up to that date, Club Log maps the GC prefix to Jersey, unless a callsign exception exists.
From 1977-01-01, the prefix for Guernsey became GU, and for Jersey GJ, and is now 2U/GU/MU and 2J/GJ/MJ respectively..
The DXCC entity of Guernsey & Dependencies comprises the islands of Guernsey, Alderney, Brecqhou, Burhou, Les Casquets, Sark, Herm, Jethou, Lihou and a number of smaller islands..
The DXCC entity of Jersey comprises the islands of Jersey, Elizabeth, Les Ecrehous, Les Minquiers, Maitresse and a number of smaller islands.
The IOTA reference for the islands of Guernsey and Dependencies is EU-114.
The IOTA reference for the islands of Jersey is EU-013, excluding Les Minquiers and Maitresse.
The IOTA reference for the islands of Les Minquiers and Maitresse is EU-099.