The series includes letters received, copies and carbons of AEF's outgoing letters, photographs, picture postcards, theatre programmes, telegrams, school and university examination papers, newspaper cuttings and documents relating to the League of Nations. Only significant correspondents are noted.

The correspondence is mainly between Felkin and his mother, Mrs Amelia Felkin, his sister Winifred, his wife Joyce and his children Hugh and Penelope. Also included are letters from the following: Will Arnold-Forster (2 autograph letters signed, c. 1924-5), Nicholas Beauchamp Bagenal (3 autograph letters signed, c. 1913-14), Hope Bagenal (1 autograph letter signed, 1929), Isaiah Berlin (13 autograph letters signed, 28 autograph postcards signed and telegrams, 3 typed letters signed, 1946-56), Francis Birrell (7 autograph letters signed, 1 autograph postcard signed, 1914-33), Kennard Bliss (5 autograph letters signed, c. 1912-14), Graham 'Gray' Carritt (42 autograph letters signed, 14 autograph postcards signed, c. 1908-14), Sir Atul Chatterjee (4 autograph letters signed, 1 typed letter signed, 1938-42), Ivy Compton-Burnett (2 autograph letters signed, 2 autograph postcards signed, 1916-46), Noel Compton-Burnett (1 autograph letter signed, 1914), Douglas Cooper (2 autograph postcards signed, 1953), Frances Cornford (1 autograph letter signed, c. 1913), Ka Cox (Arnold-Forster, 71 autograph letters signed, 2 autograph postcards signed, 1923-38), Pamela Diamand (1 autograph letter signed, 1 autograph postcard signed, 1933-6), Goldsworthy Lowes Dickinson (30 autograph letters signed, 7 autograph postcards signed, 63 typed letters signed, c. 1914-32), May Lowes Dickinson (9 autograph letters signed, 1932-8), E.M. Forster (8 autograph letters signed, 4 autograph postcards signed, 1 typed letter signed, 1930-8), Geoffrey Fry (10 autograph letters signed, 3 autograph postcards signed, 1914-17), Eric Gill (1 autograph letter signed, 1938), Florence Hardy (10 autograph letters signed, 1927-30), Jane Ellen Harrison (5 autograph letters signed, 1 autograph postcard signed, 1913-14), M.R. James (2 autograph letters signed, 2 autograph postcards signed, 1912-13), Margaret Jourdain (106 autograph letters signed, 33 autograph postcards signed, 1913-51), Richard Kahn (1 autograph letter signed, 1933), John Maynard Keynes (5 autograph letters signed, 4 autograph postcards signed, 2 typed letters signed, 1914-38), Lydia Lopokova Keynes (1 autograph letter signed, 1 autograph postcard signed, 1937-46), W.H. Macaulay (7 autograph letter signed, 1 autograph postcard signed, 1910-13), Hester [?Marsden-Smedley] (21 autograph letters signed, 2 typed letters signed, 1930-46), Herbert May (32 autograph letters signed, 15 autograph postcards signed, and telegrams, 11 typed letters signed, 1939-55), Raisley Moorsom (386 autograph letters signed, 86 autograph letters signed, and telegrams, 1913-56), Raymond Mortimer (3 autograph letters signed, 1933-5), Humphrey Noble (91 autograph letters signed, 1 autograph postcard signed, 1912-56), Philip Noel-Baker (1 autograph letter signed, 7 typed letters signed, 1929-56), Grant Richards (6 typed letters signed, 1937-8), Bertrand Russell (1 autograph letter signed, 1 typed letter signed, 1936), John Russell (19 autograph letters signed, 2 autograph postcards signed, 1946-51), Sir J. Arthur Salter (68 autograph letters signed, 9 autograph postcards signed and telegrams, 1 typed letter signed, 1922-53), Roger Senhouse (2 autograph letters signed, 1 telegram, 1 typed letter signed, 1946-8), J.T. Sheppard (7 autograph letters signed, 1915-45), Gerald Shove (1 autograph letter signed, 1913), Sir J. Hope Simpson (6 autograph letters signed, 3 typed letters signed, c. 1927-34), Rifat Tirana (2 autograph letters signed, 3 typed letters signed, 1939-41), Geoffrey Toulmin (17 autograph letters signed, 1 autograph postcard signed, c. 1913-37), Laurens van der Post (1 autograph letter signed, 1953), Hubert [Schloss] Waley (11 autograph letters signed, 1 autograph postcard signed, c. 1913-38), Rachel [Schloss] Waley (19 autograph letters signed, 1911-39), Sigi [Sigmund Schloss] Waley (4 autograph letters signed, 1933-9), Walter Westhoff (1 autograph letter signed, 1930), Lady Marjorie Williams (31 autograph letters signed, 2 autograph postcards signed, 1925-56), Sir John Fischer Williams [signature J.F.W.] (97 autograph letters signed, 4 autograph postcards signed, 1 typed letter signed, 1923-37), K. Zilliacus (8 autograph letters signed, 1 typed letter signed, 1925-36). This is a selected list of correspondents. Details of the locations of these letters are found in an index available in the Archive Centre. The arrangement of the papers has been kept chronologically by year, in the order used by Felkin. To see the complete correspondence for an individual may mean ordering several files.

Felkin organised this material into two principal systems: chronological and chronological-numerical. Within these broad methods of arrangement, he ordered his papers with varying degrees of thoroughness.
Papers relating to journals 'Vols. 1-8' (1/1/1-5 1912-29), and the years preceding them, were arranged chronologically by Felkin, and placed loose in file boxes. Documents dated 1900-15 were arranged in day, month and year sequence, those dated 1916 by month and year, and those dated 1917-29 by year only. For ease of reference, and following Felkin's overall pre-1930 system, papers relating to 1917-29, which were found in boxes by year, have been further sorted into chronological order by month. Undated material has been placed at the end of the final envelope for each year.
Papers relating to journals 'Vol. 9 Part 1' to 'Vol. 20 Part 2' (1/1/6-16 1929-42) were given consecutive identification numbers by Felkin and placed loose in file boxes. For conservation purposes, archival envelopes now divide the material into smaller chronological units. Journals for 1929-42 each contain an index aligning the document reference number with names of correspondents, or locations of photographs. Dates provided in the catalogue are only a guideline. Documents dated before and after the months cited are often included within a particular envelope because they are placed within Felkin's overall numerical scheme. Many numbers are missing from the sequence, but only significant deviations from Felkin's numbering system are noted within the list below.
Papers relating to journals 'Vol. 20 Part 3' to 'Vol. 30' (1/1/16-23 1943-55) were filed by Felkin in soft-covered folders following a broadly chronological sequence by month and year. These were not given identifying numbers, and they include papers from earlier years pinned to later correspondence. The covering dates listed below are a guideline to the predominant dates of the material within each folder.