The first three characters indicate the subject course code as indicated in the Ministry of Education Common Course Codes and/or The Ontario Curriculum Grades 11 and 12 Course Descriptions and Prerequisites.
The fourth character indicates the grade:
1 = grade 9
2 = grade 10
3 = grade 11
4 = grade 12
The fifth character indicates the course type:
O = Open courses (Grades 9 - 12)
D = Academic (Grades 9 & 10)
P = Applied (Grades 9 & 10)
L = Locally developed courses (Gr. 9 or 10)
U = University destination courses (Gr. 11 & 12)
C = College destination courses (Gr. 11 & 12)
M = University/College Destination courses (Gr. 11 & 12)