The eleventh book in James Mackay’s series on the postal history of the Scottish Islands. This volume brings together a considerable amount of new information on the postal history and postmarks of the Scottish islands, which came to light after the publication of the previous ten volumes in the series. There is also a catalogue of all the Scottish islands postal markings identified in the previous ten volumes with a scarcity rating for each postmark (this catalogue section is a listing of the code numbers given to each postmark in the previous volumes and is not illustrated, so needs to be used in conjunction with the earlier volumes).