According to the NA file nAir 35-63 : Code names for aerodrome on the continent nS.7213 dated of may 1940 canceled the previous document dated 11th April 1940 and must to destroyed.

I am not aware if archives before May 1940 have survived. If not is there anybody know what was the first date used for the code name of Rouvres A/F (n73 sqdn) which was SAMUEL ?