This is the Field Services Pocket Book, Pamphlet No. 10 as issued by General Staff Defence Headquarters, Pretoria in 1940.

For those of you who enjoy the 'Medical' side of the Military.....an interesting 44 Pages.
"Quartermaster's Comment":- Crown Copyright Reserved.......and it even has the NOT TO BE PUBLISHED Restriction at the top.......Only for those in Govt. Service......Not to the Press. How to make a Good Latrine out of an Oil Drum......with a Fly Proof Seat........would NOT I would think come into the Category of "Top Secret--Burn Before Reading"!!!!!.......but that was the way back then!!!!!
The Booklet is 182 X 124 mm and weighs in at around only 30 grams