This series contains both personal and work correspondence, being chiefly in-letters. Most of the broad divisions between family and other correspondence were made by HMC herself (HMC's file titles are given in inverted commas), and some further chronological and alphabetical sorting has been done by the Archivist within similar broad divisions. Members of HMC's extended family occasionally remain in non-family files, but where this is so, this is indicated. The series is arranged broadly chronologically, and most files of non-family correspondence are arranged alphabetically by surname. There is a gap in the chronology between 1949 and 1952: it is not clear whether letters from this period are missing, held elsewhere, or in other series under Cam 2, especially 2/6 ('European Friends').