In the early 1960s, each school year was divided into A, B, C, D, and E streams up until the 3rd year. As the groups were so large, they were again divided, typically into 3. Later the "A" "B" etc. grading was considered to be bad for children's self-esteem, so "A" "B" and "C" were replaced by "H" "P" and "S" (Holland Park School).