My sources of information are the History of the GNC by Bendall and Raybould 1919-1969 and the GNC for England and Wales syllabus of training, written in 1923 and updated in 1933 and 1939.
The subjects taught came under the headings of Anatomy and Physiology, Hygiene, First Aid, Theory and practice of nursing, Materia medica and therapeutics, Medical nursing, Surgical nursing and Gynaecology.
The examination at that time were the Preliminary, which had 2 parts. Part 1 taken after at least 6 months, unless taken prior to entry. It examined anatomy and physiology and hygiene. Part 2 was taken after 1 year and after passing part 1, it examined the theory and practice of nursing. The final exam was taken after completion of 'the prescribed period' and success in the preliminary exams. An oral exam as from 1935 was conducted by a doctor of 'good professional standard'.
School/entry qualifications were set by the hospital training school, the minimum age of entry was 18 years. In 1936 the general school certificate was advised, but not mandated. In 1937 the GCN developed an educational test, but again still not mandated. And in 1939 a pre-nursing course was introduced which could act as an entry qualification. Cheltenham Ladies College was the first 'school' to introduce such a course.