Choice blocks (CBK), streams (STM), majors (MAJ) and sub-majors (SMJ) are groupings of subjects that form part of the course structure. They are collectively called sub-structures.
Sub-structures are used to specify the completion requirements for a particular course and appear in the course structure and course program of the detailed course entry.
With the exception of choice blocks, which consist entirely of an option list from which a specified number of credit points must be selected, each of these sub-structures can include core components, optional components or both. The components may be subjects or further sub-structures.
The breakdown of the subjects students are required to complete within a particular sub-structure is provided in code-numeric order in the study package directory. The credit-point value of the options available is always specified but, in some cases, no subjects or only a partial list of subjects are specified under the list of valid choices. This is the case when students have considerable flexibility as to what subjects they choose. Once permission from the relevant faculty has been obtained, the chosen subject can be made available to the student by being added to the appropriate list on the student's study plan.