These photographs – from a report on the physical examination of men of military age by National Service Medical Boards – illustrate the system of grading applied to military recruits during World War I. The classification seen here replaced the previous A-D version, which was divided into four sub-categories (e.g. B1, B2, B3 and B4). By reducing the classifications to only four grades, the new simplified system enabled many more men to be recruited to the front. Grade II absorbed many men who had some disability but sufficient fitness for garrison service abroad or at home. Grade III included men who were unfit in varying degrees and ways but were still able to serve as auxiliary troops, sanitary inspectors, cooks and clerks, etc.

Specimens of men in each of the four grades, 1920
Photographs from a report by the Ministry of National Service.

Specimens of Men in Each of the Four Grades
CC BY: Wellcome Library, London
https://wellcomecollection.org/articles/war-and-body