Question about Imperial War Museum marginalia

[eddien]

Hello fellow WWI flight enthusiasts!

I'm doing some research on No. 30 Squadron and the air campaign in Mesopotamia for a creative project (I'm aiming to write a short science fiction story partly based around this conflict.) I've read through Tennant's "In The Clouds Over Baghdad" which was excellent and am now going through a printing from the Imperial War Museum called "History of No. 30 Squadron."

In the margins of the printing, along with the months like "September 1917." there are other notes e.g. "209/24/16." "21/6/87." "209/22/12.". I'm thinking they may be references to pages from official reports, pilot notebooks, or other sources; but the printing itself as yet offers no explanation of their meaning nor a list of sources.

Does anybody know what these refer to? If they indeed are first-hand sources, is it possible for a layperson to access them?

[eddien]

Just to follow up on this, these are likely reference numbers that have been renumbered on moving to the catalog at The National Archives.

209/24/16 = A.H.B. Reference 209/24/16 = AIR 1/2202/209/24/16: War Diary, April 1916, Assistant Director Aviation IEF "D" R.F.C.

21/6/87 = A.H.B. Reference 21/6/87 = AIR 1/674/21/6/87: The campaign in Mesopotamia, 1914-1918

209/22/12 = A.H.B. Reference 209/22/12 = AIR 1/2200/209/22/12: War Diary, May 1916, 30th Squadron


Other such references can be found by the search page at https://discovery.nationalarchives.gov.uk/