a. A course tagged compulsory(C) must be taken and passed at minimum of 40%
b. A course tagged required(R) must be taken and passed at not less than 30%
c. A course tagged elective (E) may be taken but need not be passed at 40% level.
But whether passed or not, having been taken, it is included in the computation of results.
d. Pre-requisite –A course whose knowledge is essential and must be passed prior to taking      another specified course.

When a compulsory course is passed at 30%, (but less than 40%), the candidate is qualified to take the higher courses for which the course is a pre-requisite. However, it must be repeated until it is passed at not less than 40%level.