The correspondents are:
Dr Don McLeod, Dr John Maddox, Professor Marvin W Makinen, Dr Jaroslav Malina, Adrian Malone, Dr and Mrs P J Marcer, Dr Boleslaw Marczynski, Dr Henry Margenau, Carole Markin, Dr Robert Maslansky, Donna Matthews, Alice E Mayhew, Dr William H McClain, Dr Michael McClure, Robin McConnell, Suzanne P McKee, Dr George F Cahill Jr (concerning articles by Dr Victor McKusick), Theodore Melnechuk, Leslie Meredith, Dr Danielle Mihram, Professor Ian Millar, Dr Jeffrey Miller, Dr Stanley Miller, D R Mills, Peter Mitchell, Professor Graeme Mitchison, Modern Maturity published by the American Association of Retired Persons, Dr Alan Moffit, James Morgan, John Moody, Tito Franklin Morales, Mr Coutsocheras (Mouvement pour la mise hors commerce), and John Morrison.
A letter containing sensitive personal information has been extracted to file PP/CRI/J/1/2/20.
A floppy disk labelled 'Letter and book ms. from McDonald 1988' has been catalogued separately as file PP/CRI/J/1/2/11A.