This page is most definitely work in progress!
Drafts of men of the Royal Army Medical Corps that were proceeding overseas were coded by letters. As I come across specific examples, I am adding them to this page.
France and Flanders
DD: Southampton to Rouen, ship “Princess Victoria”, 26-27 October 1915
KKK: Southampton to Rouen, 29-30 January 1917
PPP: Southampton to Rouen via Le Havre, 20-23 April 1917
MXX: Southampton to Le Havre “Mona’s Queen” 24 June 1917, thence Marseilles 29 June 1917 “Huntsgreen” to Alexandria.